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i/O

JOURNAL "-^^

OF THE

AssoGlaiioi o[ EoijtaiD!! Societies.

Boston. Cleveland. Minneapolis. St Louis.

Montana. St. Paul, Detroit. Pacific Coast.

Buffalo. Louisiana. Cincinnati.

CONTENTS AND INDEX.

VOLXJMK XXIII.
July to December, 1899.

PUBLISHED BY

THE BOARD OF MANAGERS OF THE ASSOCIATION OF
ENGINEERING SOCIETIES.

John C. Trautwine, Jr., Secretary, 257 S. Fourth Street, Philadelphia.

<^.

CONTKNTS.

VOL. XXIII, July-December, 1899.

por alphabetical index, see page v,
No. I. JULY.

PAGE

Covered Reservoirs and Their Design. Freeman C. CoMn I

Field Notes of a Civil Engineer. — Do They Belong to His Client or to

Himself? /. Vander Hoek 32

Mechanical Draft. Henry B. Prather 48

Discussion. Messrs. Rodgers and Holloivay 55

Proceedings.

No. 2. AUGUST.

Forest Management in Maine. ' Austin Cary 57

Power Development at Niagara Falls other than that of the Niagara

Power Co. PV. C. Johnson 78

Discussion. Messrs. Bassett, Johnson, Smith, Guthrie, Rogers,

McCulloh ; 88

Paving Brick and Brick Pavements. H. J. March 91

Discussion. Messrs. Richer, March, Mann, Guthrie, Green,
Norton, Vander Hoek 112

Proceedings.

No. 3. SEPTEMBER.

Covered Reservoirs. Frank L. Fuller iig

Locks and Lock Gates for Ship Canals. FIcnry Goldmark 132

Proceedings.

No. 4. OCTOBER.

The Flow of Water in Pipes. C. H. Tutton 151

The Design and Construction of a Modern Central Lighting Station.

H. H. Humphrey 166

Proceedings.

IV ASSOCIATION OF ENGINEERING SOCIETIES.

No. 5- NOVEMBER.

PAGE

Alternating-Current Power Motors. W. A. Layman 195

Patents and Monopoly. John Richards 217

Proceedings.

No. 6. DECEMBER.

The Influence of Mechanical Draft upon the Ultimate Efficiency of

Steam Boilers. Walter B. Snow. . . .-. 227

Water Waste. Joseph C. Beardsley 248

Grade Crossings. A. Mordecai . 255

Discussion. H. C. Thompson 259

Proceedings.

INDEX.

VOL. XXlll, July-December, 1899.

The six numbers were dated as follows :

No. I, July. No. 3, September. No. 5, November.

No. 2, August. No. 4, October. No. 6, December.

Abbreviations. — P == Paper; D = Discussion ; I ^= Illustrated.
Names of authors of papers, etc., are printed in italics.

PAGE

Alternating-Current Power Motors. W. A. Layman. .P., I., November, 195

Ijeardsley, Jos. C. Water Waste P., December, 248

Boilers, Steam, Influence of Mechanical Draft upon the Ultimate

Efficiency of . Walter B. Snow P., I., December, 227

Brick, Paving, and Pavements. H. J. March. .. .P., D., I., August, 91

(^anals, Ship, Locks and Lock Gates for . Henry Goldmark.

P., September, 132

Gary, Austin. Forest Management in Maine P., I., August, 57

Coffin, Freeman C. Covered Reservoirs and Their Design. .P., I., July, i

Covered Reservoirs and Their Design. Freeman C. Coffin. .P., I., July, i

Covered Reservoirs. Frank L. Fuller P., I., September, 119

Crossings, Grade . A. Mordecai P., December, 255

jjesign and Construction of a Modern Central Lighting Station.

H. H. Humphrey P., L, October, 166

Draft, Mechanical Influence of upon the LUtimate Efficiency of

Steam Boilers. Walter B. Snow P., I., December, 227

Draft,' Mechanical . Henry B. Prather P., D., July, 48

Xlffficiency of Steam Boilers, Influence of Mechanical Draft upon the

Ultimate . Walter B. Snow P., I., December, 227

r* ield Notes of a Civil Engineer. — Do They Belong to His Client or

to Himself? /. Vandcr Hoek P., July, 32

Flow of Water in Pipes. C. H. Tutton ' P., I., October, 151

Forest Management in Maine. Austin Cary P., I., August, 57

Fuller, Frank L. Covered Reservoirs P., I., September, 119

(V)

VI ASSOCIATION OF ENGINEERING SOCIETIES.

PAGE

ijates, Locks and Lock for Ship Canals. Henry Goldmark.

P., September, 132
Goldmark, Henry. Locks and Lock Gates for Ship Canals.

P., September, 132
Grade Crossings. A. Mordecai P., December, 255

tlumphrey. H. H. Design and Construction of a Modern Central

Lighting Station P., I., October, 166

Influence of Mechanical Draft upon the Ultimate Efficiency of Steam

Boilers. JV alter B. Snozv P., L, December, 227

Johnson, IV. C. Power Development at Niagara Falls other than that

of the Niagara Power Co P., D., August, 78

l^ayiiidii, Jl\ A. Alternating-Current Power Motors. .P., I., November, 195

Lighting Station, Modern Central, Design and Construction of a .

H. H. Humphrey P., L, October, 166

Locks and Lock Gates for Ship Canals. Henry Goldmark.

P., September, 132

JVlaine, Forest Management in . Austin Gary P., I., August, 57

March; H. J. Paving Brick and Brick Pavements. . . .P., D., I., August, 91

Mechanical Draft, Influence of upon the Ultimate Efficiency of

Steam Boilers. Walter B. Snozv P., I., December, 227

Mechanical Draft. Henry B. Prather. P., D., July, 48

Monopoly, Patents and -. John Richards P., November, 217

Mordecai, A. Grade Crossings P., December, 255

Motors, Alternating-Current Power . IV. A. Layman.

P., I., November, 195

jVJ^iagara Falls, Power Development at other than that of the

Niagara Power Co. IV. C. Johnson P., D., August, 78

Notes, Field of a Civil Engineer. — Do They Belong to His Client

or to Himself ? /. Vander Hoek P., July, 32

Patents and Monopoly. John Richards P., November, 217

Paving Brick and Brick Pavem^nti,. H. J. March. . . .P., D., I., August, 91

Pipes, Flow of Water in . C. H. Tutton P., I., October, 151

Power Development at Niagara Falls other than that of the Niagara

Power Co. W. C. Johnson .P., D., August, 78

Power Motors, Alternating-Current . W. A. Layman.

P., I., November, 195

Prather, ILcnry B. Mechanical Draft P., D., July, 48

XVeservoirs, Covered and Their Design. Freeman C. CofRn.

P., I., July, I

Reservoirs, Covered- — . Frank L. Fuller P., I.. September, 119

Richards, John. Patents and Monopoly P., November, 217

INDEX. VII

PAGE

Ohip Canals, Locks and Lock Gates for . Henry Goldmark.

P., September, 132
Snoiv, Walter B. Influence of Mechanical Draft upon the Ultimate

Efficiency of Steam Boilers P., I., December, 227

Station, Modern Central Lighting, Design and Construction of a — — .

H. H. Humphrey P., I., October, 166

Steam Boilers, Influence of Mechanical Draft upon the Ultimate Effi-

cency of . IValter B. Snozv P., I., December, 227

Swan, Charles Herbert, Memoir of Procs., September, 6

1 utton, C. H. Flow of Water in Pipes P., I., October, 151

V ander Hoek, J. Field Notes of a Civil Engineer. — Do They Belong

to His Client or to Himself? P., July, 32

Water, Flow of in Pipes. C. H. Tutton P., I., October, 151

Water Waste. Jos. C. Beardsley P., December, 248

i'\

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

Ass

OCIATION

OF

Engineering Soci£II£S.

Organized 1881. ^-^^V-* 'V^

Vol. XXIII. JULY, 1899. t '-'• AUG ? 0 lS89i. &.

This Association is not responsible for the subject-matter^5*SgtriDuta5^yrarf5'^B^i«C^ 05
for the statements or opinions of members

■;

COVERED RESERVOIRS AND THEIR DESIGN.

By Freeman C. Coffin, Member, Boston Society of Civil Engineers.

[Read before the Society, May 17, 1899.]

The use of covered masonry reservoirs for the storage and
distribution of underground water is becoming so general, wher-
ever the elevation and local conditions admit, that a brief considera-
tion of the reservoirs of this class which have been built, a study
of the elements which enter into the design and an investigation of
the cost of various sizes and depths of such reservoirs can hardly
fail to be of interest.

Stand pipes, tanks or metal structures of any description,
although used for the same purpose as earth or masonry reservoirs,
are of a nature so essentially different that further reference to them
is unnecessary in this paper. The covered reservoir is in the line
of natural evolution from the open distributing reservoir, to meet
the requirement of exclusion of light from underground or filtered
water, although the necessity of providing a roof or covering of
some kind leads to a different disposition of materials.

SOME EXISTING RESERVOIRS,

In referring to reservoirs that have been built no attempt will
be made to treat the subject exhaustively, nor to go to ancient his-
tory for examples. A few prominent types will be very briefly
described.

SOME ENGLISH RESERVOIRS.

In the Proceedings of the Institution of Civil Engineers, Vol.
LXXIII, in the year 1883, Mr. William Morris describes a number

2 ASSOCIATION OF ENGINEERING SOCIETIES.

of covered reservoirs built in England. In the discussion that fol-
lows several others are described. Among them is nearly every
type of roof covering that has since been built in this country.
The arches of these roofs were all of the segmental barrel form.
Their spans were from 7 to 17 feet in the clear, their rise from one-
eighth to one-third of the span. In the earlier examples the arches
were sprung from wrought iron girders, these in turn being sup-
ported by cast iron pillars. In later construction brick piers were
substituted for the pillars, and later still brick lintel arches spring-
ing from brick piers supported the main arches. No groined arches
were included among these examples of reservoir vaulting.
Although concrete is employed extensively in the construction of
the reservoirs, it is used in the covering arches in only two instances.
Except for the spandrel filling, they are of brick in the others. In
the cases where concrete was used the clear spans were 12 feet, and
the rise 2^ feet in both. In one it was 9 inches thick at the crown
and 18 at the skewback, in the other 10 and 20 inches respectively.
But two of these reservoirs were circular in plan, the others being
square or rectangular. In one of the circular ones the covering
arches were concentric, and were supported on rings made of 12-
inch iron I beams resting upon brick piers. The other round
reservoir had a vaulting of unique design. It was 64 feet in
diameter, constructed with nine radial arches springing from 12-
inch I beams, which rest upon a large cast iron column in the center
and upon the outer walls. The iron girders have a slope of 4 feet
from the center to the wall. The arches have a span of 22 feet and
a rise of 4 feet at the wall ; the crown is level, while the span and
rise diminish to nothing at the center. The thickness of nearly all
of the arches was about 8 inches, or two rings of brick laid on edge.

The side walls were generally rather heavy. In one reservoir
they were very light. These were of brick 14 inches thick, built in
the form of vertical arches, with 10- foot span and a very slight rise.
There was a brick buttress or pier at the springing of each arch.
This form being designed to resist the pressure from the outside, it
is evident that the inside pressure of the water was supported by
the earth backing. These reservoirs are described in detail in the
paper, and are illustrated by plates. English practice of that date
is quite fully described in the paper and the discussion that follows.

In a paper published in the journal of the N. E. Water Works
Association for September, 1888, Mr. Charles H. Swan describes
some very interesting covered reservoirs in France. The following
extract from his paper refers to one of the most striking features
of the reservoir of Menilmontant : "The reservoir is covered by

COVERED RESERVOIRS AND THEIR DESIGN. 3

groined arches composed of two course3 of bricks laid flat in
cement. They rest upon pillars 60 centimeters (2 feet) square and
6 meters (20 feet) between centers. . . . The brick arches are
about 8 centimeters (3^ inches) in thickness, including the plaster-
ing. They were covered by a layer of earth and turf 40 centimeters
(16 inches) thick."

AMERICAN RKSERVOIRS.

There are at present a number of covered reservoirs in this
country. The following is a brief description of several of these:

Nezvton Reservoir.

One of the earlier of these was built for the water works of
the city of Newton, Mass., in 1890 and 1891. It was designed and
built by Mr. Albert F. Noyes, city engineer. It is about 125 feet
wide by 175 feet long and 15 feet deep. The walls are of rubble
masonry, laid in Rosendale cement mortar, about 7^ feet thick at
the bottom and 2^ feet on top on two sides and 5 feet on the other
two. The covering is of brick arches 4 inches thick, with a clear
span of 10 feet and about 10 inches rise. The arches are supported
by rows of lintel arches of brick, which rest upon brick piers 20
inches square. The top of the arches is filled up level with con-
crete to a point 4 inches above the crown. Over this is a filling of
earth about 2^ feet thick.

Brookline Reservoir.

A covered reservoir was constructed for the water works of
Brookline, Mass., in 1892. It is about 92 feet square and 19 feet
deep ; its construction is similar to that at Newton, except that the
walls and piers are heavier. A description of it is given in a paper
read by the engineer, Mr. F. F. Forbes, and published in the
journal of the N. E. Water Works Association for March, 1894.
These reservoirs are excellent examples of substantial construction.

Franklin Reservoir.

In the year 1891 Mr. F. L. Fuller, civil engineer, built a reser-
voir of admirable design and economical construction at Franklin,
N. H. It is circular in plan, 70 feet in diameter and about 17 feet
deep. The walls are of rubble masonry laid in Rosendale cement
mortar, are 5 feet thick at the bottom and 2^ feet at the top. The
covering consists of two concentric brick arches and a central dome.
The latter is 23 feet in diameter, with a rise of 3.25 feet. The
arches have a clear span of 11 feet, and rise 1.50 feet; the thickness
of the arches and dome is 8 inches. They are supported by two

4 ASSOCIATION OF ENGINEERING SOCIETIES.

rings of lintel arches and the side walls ; the piers of the lintels are
of brick, i foot square and 7 feet apart in the rings. The piers are
much smaller for their load and length than it is customary to make
them, and are certainly an interesting example of the extent to
which ordinary practice can be departed from with success. Mr.
Fuller has since built similar ones at Methuen and Winchendon,
Mass. A description of this reservoir is given in the journatl of
the N. E. Water Works Association, 1892, page 82.

Waltham Supply Well.

In the journal of the N. E. Water Works Association for
March, 1894, there is an interesting description of the covering of
a supply well at Waltham, Mass., by Mr. Frank P. Johnson, civil
engineer. There are arches similar to those at Newton and Brook-
line ; these have a clear span of 11.5 feet, rise of 1.92 feet and are
built of one 4-inch ring of brickwork with no concrete filling over
them. There is also a circular dome 40 feet in diameter, 7 feet
rise, built of what were called Guastavino tiles i inch thick ; there
were three thicknesses of these tiles in the domed covering. They
foot at the skewback on a metal ring, which resists the outward
thrust.

Welle sley Reservoir.

During the summer of 1898 the writer constructed some works
for an additional supply of water for the town of Wellesley, Mass.
The supply is an underground one, which was recommended by
Mr. Desmond FitzGerald after a thorough investigation of all
available sources. A covered reservoir of a capacity of 600,000
gallons was included in his recommendations. Mr. FitzGerald
acted as consulting engineer in the design and construction of the
works.

In designing the reservoir many types were considered, and
it was finally decided to build it circular in plan, with a roof or
covering of elliptic groined arches. It was first thought that such
arches were not adapted to a circular reservoir, but further study
showed that no real difficulties were involved. Designs for
several depths were computed, and it was found that a depth of
about 15 feet and diameter of about 80 feet was more economical
for the required capacity than a greater depth. The dimensions
of the arches and piers finally adopted fixed the inside diameter at
82 feet, and the depth from the floor to the springing line of the
arches was made 15 feet. For a capacity of 600,000 gallons the
water line is about 0.7 feet above the spring line, and the overflow
Avas fixed at that point. Material for concrete was more available

COVERED RESERVOIRS AND THEIR DESIGN. 5

than for rubble masonry, and the walls were designed of that ; it
was also decided to make the roof of concrete, as its cost is much
less per yard than brickwork; and with the latter the thickness of
the arches could not be made much less, besides this form of arch
requires a great deal of cutting of the brick. The centering for
concrete costs more, as it must be made tight and smooth ; while
that for brick can be made with a covering of narrow strips. Brick
was chosen for the piers. The dimensions of the parts of the
reservoir as designed were as follows :

Walls 15 feet high from floor to spring line, 2 feet thick for
5 feet below^ the spring line, 2.67 feet in the next lower 5 feet, 3.33

Interior of Reservoir Showing Groined Arches.

feet in the lowest section. Piers 15 feet total height, 2 feet square,
w'ith a base 2.67 feet square at bottom. Foundations of piers 3.5
feet square, i foot deep. Roof arches 12 feet clear span, 2.5 feet
rise, 0.5 feet thick at the crown, filled in level over the piers. The
material of the excavation was a tight, clayey hardpan with very
little water in it ; the floor was therefore made only 4 inches thick.
A steel ring of channel iron, weighing 32 pounds per foot, was set
in the side walls just above the spring line. The earth filling over
the concrete roof was designed as follows : Six inches of clean
gravel next the concrete for drainage, and to prevent freezing to the
concrete; this gravel went over the sides to the spring line, and was

6 ASSOCIATION OF ENGINEERING SOCIETIES. ,

drained by several lines of 4-inch vitrified pipe, which discharge
at the toe of the embankment. Over the gravel i foot of earth from
the excavation and then 6 inches of loam, making a total of 2 feet.
The embankments were carried out at the level of the top to a
point 7 feet outside of the inside line of the wall, and thence to the
natural surface with a slope of 2 to i.

The construction was executed as designed, with two ex-
ceptions. A great many bowlders were found in the excavation;
the specifications provided that "the lower part of the wall might
be made of these stones if the engineer should so direct, in wjiich
case it is probable that the thickness of the wall will be increased."
This was done, and the wall made 4 feet at the bottom, or 8 inches
thicker than designed, as shown in Fig. i. It was thought that it
would not be possible to make as strong work with these bowlders
as with concrete. The smooth, rounded stones were split, the
rubble laid against forms and so carefully bedded in the mortar that
the writer is of the opinion that it would have been perfectly safe
to have used the thickness designed. The other change was in the
thickness of the earth covering. There being a surplus of loam, it
was put on i foot thick, instead of 6 inches. This made the total
thickness of the earth 2^ feet at the walls and 3 feet at the center.

Portland cement was used throughout. That in the walls was
the Brooks-Shoobridge brand ; the vaulting was of Alsen, with the
exception of about one hundred barrels of Atlas that was used
becjruse the Alsen could not be had in time. The concrete made of
the Atlas seemed quite as good as the other. The number of parts
of sand used to one part of cement were as follows: In rubble
masonry 2^, in the concrete in the walls 3, in the vaulting 2^. The
proportion of screened gravel used in the concrete was such that
the voids were slightly overfilled. It required approximately i.i
barrels of cement per cubic yard for the rubble masonry, 1.2 barrels
for the concrete, with 3 parts of sand, and 1.3 for that with 2^ parts.
These figures are based upon the total amount of each kind of
work and the number of barrels used in that work.

A ring made of channel iron, weighing 32 pounds per foot,
was set in the side walls, with its bottom at the spring line of the
roof arches. The bottom of the reservoir is covered with a floor
of concrete 4 inches thick. This floor and the side walls are finished
with two coats of plaster ; one about -J inch thick, of mortar mixed
in the proportion of 2 of sand and i of cement ; this coat was leveled
up, but not smoothed. The last coat was of neat cement, about ^
of an inch thick, thoroughly rubbed in and smoothed with trowels.
There were a few places where the walls were moist from the pres-

COVERED RESERVOIRS AND THEIR DESIGN. 7

sure of the water on the outside, and some trouble was anticipated
in making a good work with the plastering; but very little was
realized, and it was in the best of condition when the reservoir was
filled. The roof was not absolutely tight, and a very heavy rain
coming on just as the plastering of a part of the floor was finished,
there was some dropping of water in several places, which cut
through the -J-inch coat before it was hard and threw off a number
of flakes. This made it necessary to plaster over a small portion of
the floor. Twelve hours more of setting before the rain would
have prevented this ; the expense was, however, but a few dollars.
The centering for a roof of this type is an important and
expensive factor in the work. Plans were made for centers that
would each cover the space between four piers. The contractor
believed that it would be better to reduce the size of the single
centers, and, as he was not required to adopt the plans of the engi-
neer if his own were satisfactory, he was allowed to use the smaller
ones. The writer believes that the extra fitting caused by this
change made the total cost of the centering much more than it
would have been if the original plans had been followed. Whether
this is so or not, the cost of the centers (if used but once), of the
supporting timbers and the labor of erection and removal was
about 22^ cents per square foot for the inside area of the reservoir.
The contractor's plan was to supply centers for one-quarter section
of the reservoir only, and put the roof on in such sections. This
was assented to by the engineer, with the provision that the heads
of the piers should be thoroughly braced in each direction to the
outside walls, and that if it was found necessary to have more
centers in order to prevent delay they should be provided.
Although a large saving in cost of centers would be made in this
way, it is a mistaken poliicy, as it afterwards proved in this case.
While it is quite possible to do the work in this way if the piers are
braced and kept braced, there is a liability that the braces may be
removed without the knowledge of those who realize the danger of
their removal, as happened here. When one-half of the reservoir
had been arched over in quarter-sections at a time, and the centers
were being set for the third section, the center row of piers, or
those supporting the outer edge of the finished half of the roof,
were overturned, and the arches between them and the next row
fell, killing one man, breaking the leg of another and slightly injur-
ing two more. It was just after seven o'clock, and neither the
contractor nor the inspector was present. It was found upon
investigation that three and, as two of the carpenters testified, four
out of five braces that resisted the thrust on this row of piers had

ASSOCIATION OF ENGINEERING SOCIETIES.

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COVERED RESERVOIRS AND THEIR DESIGN. 9

been removed. It transpired afterwards that the braces had been
removed from the first section in the same way, and the tensile
strength of the concrete was sufficient to keep the arches intact.
There was a greater load on the half-section, as a portion of the
covering had been put on.

With the exception of this unfortunate accident, the work on
the reservoir was very successfully carried out. The contractor,
'Sir. Donato Cuozzo, took a great personal interest in having the
character of the work of the very best, and used every effort to
make it so. When finished the reservoir was filled and allowed to
stand for some weeks without any draft upon it ; there was practi-
cally no loss of water from it. The effect upon the water, as shown
by a chemical analysis, of standing without change in this new
reservoir was marked. The cause of this has never been explained.
The results of the analyses on the preceding page (made by the
State Board of Health) show in what way it was affected.

A plan and section of this reservoir is shown in Fig. i.

The reservoir has now been in use about fifteen months with
satisfactory results. The final cjuantities, their contract price and
the total cost of the reservoir, aside from any expense caused by the
accident, are given below :

3446.20 cubic yards earth excavation @ $0.40

24.50 " " rock " @

309.80 " " rubble masonry @

502.86 " " concrete @

61.22 " " brick @ 10.50

143.30 " " gravel (ci).

484.50 square " plastering wall @

570.30 '■ " " floor Cro

438.60 cubic " loam in place @

Setting pipes, gates, etc

Seeding and sodding

148. vitrified pipe @

Channel iron ring

Bracing, sheeting and centers

Payment to contractor $6,291.91

In addition to the above there are the following items that

were outside of the contract :

Portland cement $3,156.18

Cast iron pipe, special castings, gates and gate boxes 4643-

Special ironwork 77-34

Hauling sod 21.38

Gravel in the pit 65.00

Carpenter work on brick house for telemeter 138-93

I beams for same 24.00

Telemeter transmitter and wiring 70.80

Blacksmith work i5-O0

Sodding not done the first season about 90.00

Total of extra items $4-122.95

Total cost $10,414-86

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96.90

.20

114.06

.20

87.72

100.00

60.00

-25

37.00

350.00

500.00

10 ASSOCIATION OF ENGINEERING. SOCIETIES.

THE DESIGN OF COVERED RESERVOIRS AND WATER FILTERS.

The controlling factors in the design of covered reservoirs for
water or sewage and in that of the structure that contains the filter-
ing materials or the filter bed in a water filter of the "sand filtration
type," where the latter must be covered, are so similar that the
design of both can very well be treated in the same paper. The
following discussion of such design is intended to refer to both in
so far as it relates to their common features. It will be readily
perceived when the discussion refers to considerations peculiar to
only one of the subjects, as, for instance, that in regard to the
economic ratio of depth to area, which refers only to the reservoirs.
For convenience, the word reservoir will be used in referring to the
subject of the paper.

The required capacity of the proposed reservoir having been
determined, which determination is independent of the design of the
reservoir itself, its form is naturally the first question to be con-
sidered. If the choice is not restricted by topography or property
lines, either the square or circular form would naturally be chosen.
Which of these is the more economical may depend upon local
conditions, the relation of depth to area, or to other factors in the
case. The natural inference is that the circular form would require
less materials in its construction. Where land is expensive the
square one might be the cheaper. The cost of each type under
various conditions will be given in this paper. As the form departs
from the square or the circle the cost increases for the same
capacity, since the length of the side walls is greater in proportion
to the inclosed area ; therefore economical design does not permit
a departure from these two forms except where it is rendered neces-
sary by the shape of the lot or the topography of the ground.

The relation of depth to area must next be determined ; there
seems to be nothing to indicate with any certainty what this ratio
may be. The amount of excavation is about the same for any
ratio; the cost of the roof, floor and piers will increase directly
with increasing area ; the cost of the side walls increases about as
the square root of the area. On the other hand, an increase in
depth involves an increase in the cost of the walls, which is greater
than that of their depth, owing to the increasing thickness of the
bottom. In an absolutely scientific design the material in the piers
will increase faster than their depth, due to the necessity of making
their horizontal dimensions greater as their length increases. If
not altogether impossible, it would be very difficult to construct a
formula that would combine all of these factors and give the
economic ratio. An endeavor will be made in this paper to pro-

COVERED RESERVOIRS AND THEIR DESIGN. ii

vide a means of ascertaining this ratio for certain types of reser-
voirs without having- recourse to the tedious method of designing
and estimating upon several reservoirs of different dimensions. In
the discussion of the design of a reservoir the several parts will be
treated separately.

ROOF^ OR VAULTING.

The design of the vaulting is more independent than that of
the other parts, and their design is largely influenced by it ; there-
fore the first consideration will be given to it. This paper is
intended to treat wholly of masonry or imperishable construction,
and no attention will be given to roofs of other types, although
such may be quite satisfactory under some conditions.

The choice of material for the arches is practically confined to
two kinds. Brick is the material of which most of the covering
arches have been made. The use of concrete is increasing rapidly
at the present time, and, when properly made with Portland cement,
it cannot be surpassed. Its cost per cubic yard is about one-half
that of brick masonry, and it is not necessary to use a greater
quantity than of the latter. However, either makes an excellent
vaulting, and the choice may often depend upon the local availability
of the material. Concrete was used in the arches of the Wellesley
reservoir, and in one built by Mr. F. L. Fuller for the State Hospital
for Epileptics at Palmer, Mass. The vaulting of filter beds Ijuilt
by 3*Ir. Allen Hazen at Albany is also of the same material. A
sewage reservoir that is being built at Clinton by the Metropolitan
Water Board is to be covered with concrete. As concrete can be
placed in any form with little trouble, almost any type of arch may
be selected. Consideration must of course be given to the com-
parative difficulty of making the centers.

Groined elliptic arches offer many advantages: the quantity
of the material required is small ; there is a clear head room in each
direction, which is not the case with barrel arches ; and the arrange-
ment is good for ventilation. With groined arches both lintel
arches and iron girders are avoided. This type was adopted by
Mr. Wm. Wheeler in the composite brick and concrete arches of
the filter beds at Ashland, Wis., and Somersworth, N. H. It was
also adopted for the concrete arches of the Wellesley and Clinton
reservoirs, and by ]\Ir. Hazen for the Albany filters. The dimen-
sions of the arches in the first two instances were as follows :
Clear span 13.75 ^^^t, rise 3.50 feet, thickness at crown about 5
mches, or the thickness of two bricks laid flatwise. By a curious
coincidence, which was the result of independent study, the Welles-
ley and Albany arches have exactly the same dimensions, — namely.

12 ASSOCIATION OF ENGINEERING SOCIETIES.

clear span 12 feet, rise 2.50 feet, thickness at the crown 0.50 feet.
In the CHnton reservoir the span and rise is to be the same, and the
thickness of the crown is to be i foot. The thickness of the earth
covering is about twice as great as in the other cases. This study
of design will be limited to elliptical groined arch vaulting, with
especial reference to the use of Portland cement concrete.

The determination of the unit pressures is rather uncertain.
When built of concrete, and to a certain extent when built of brick
in cement, an arch of this form is monolithic, and a portion of the
internal stress is resisted by the tensile strength of the material,
instead of being wholly in compression, as in a barrel arch. The
stresses, in a section of the arch normal to the axis and in line with
the piers, are probably compressive in as far as they are caused by
the load upon that section. Since there is no diagonal rib or arch

Fig. 2.

at the groin to carry the pressures caused by the load on the flanks
of the arches to the piers, these pressures must be distributed by
the tensile strength of the material between the normal arch and a
certain portion of the groin in a way that would seem to defy
mathematical treatment.

It is impossible, however, to secure a bond between new work
and that already set, in which the adhesion of the new to the old
is equal to the cohesion in the body of the material. In work of
much extent such bonding cannot be avoided. Contraction cracks
are also quite sure to occur in large areas of masonry. In view of
these considerations, it is probably wise to neglect the tensile
strength, or at least give it but little weight, and, if any considera-
tion is to be given to computed pressures, to calculate them approxi-
mately, under the most unfavorable conditions.

COVERED RESERVOIRS AND THEIR DESIGN. 13

The load on the arches is their own weight, that of the earth
covering, the water that it holds in saturation, ice and snow and
whatever load of people may come upon it. As a distributing reser-
voir is usually in a sightly place, the last item must be given due
weight, unless thorough provision is made to exclude them.

Fig. 2 shows a section, normal to its axis, of an arch with a
clear span of 12 feet, rise of 2.50 feet and thickness at crown of 0.50
feet ; also a graphical representation of the pressures in a unit
section of i foot. These dimensions are taken as being identical
with two recent examples actually built, with the exception of the
thickness, of one that is being built and because there seem to be
reasons for using about these dimensions. (The latter is opinion
only, and cannot be demonstrated except by a great deal of work in
designing and computing those of different dimensions and estimat-
ing their effect upon other parts of the reservoir.)

Table No. i gives the loads, and Table No. 2 gives the unit
pressures at the different points of the arch shown in Fig. 2.

Table No. i.
Loads on Normal Arch.

Area of Wt. of Wt. of Wt. of Wt. of Total Total

No. of Concrete, Concrete, Earth, Snow and People, Weight, Weight,

Sect. Sq. Ft. Lbs. Lbs. Ice, Lbs. Lbs. Lbs. Tons.

1 0.52 78 250 25 50 403 .202

2 0.60 90 250 25 SO 415 .207

3 0.72 108 250 25 50 433 .216

4 0.97 145 250 25 50 470 .235

5 L34 201 250 25 50 526 .263

6 1.98 297 250 25 50 622 .311

7 2.25 337 187 19 38 581 .290

Total load on one foot section of half-arch 1-724

Table No. 2.
Average Unit Presstires on Nominal Arch.

Total Press. Area of Average Unit Pressure

No. of on Joint, Joint, per Sq. In., per Sq. Ft.,

Joint. Tons. Sq. Ft. Lbs. Tons.

1 2.26 0.50 62.80 4.52

2 2.29 0.53 60. 4.33

3 2.33 0.56 57.60 4.15

4 2.41 0.59 57- 4-10

5 2.52 0.62 56. 4.03

6 ,... 2.67 0.70 53. 3-8i

7 2.90 1.33 30.20 2.18

At crown 2.25 0.50 62.50 4.50

As the arch proper and the spandrel filling are one mass, in

computing the pressures the extrados of the arch must be assumed.

In Fig. 2 a thickness was found by trial in which the unit pressures

would nowhere exceed that at the crown, and in which the line of

pressure would lie wholly within the middle third. The average unit

14 ASSOCIATION OF ENGINEERING SOCIETIES.

pressure at the crown is 4.50 tons, and as the hne of pressure at this
point is one-third of the thickness from the outside ; if the material
is considered as inelastic the maximum unit pressure will be twice
the average, or 9 tons. This is probably the greatest pressure in
the arch. The line of pressure is also at one-third of the thickness
from the soffit near the point called joint 5. At all other points
the line of pressure is well within the middle third, and the maxi-
mum pressures are less. There seems to be no way in which the
unit pressures in the groin can be determined with much pre-
cision, as there is no separate rib or arch in which to compute
them. If a width is assumed for a rib the pressures in it are
modified by the tensile strength of the material of which it
is a part; this must prevent the result from being even ap-
proximately correct. The unit pressures at and near the groin
are probably slightly in excess of those in the normal arch. This
opinion is based upon some rough approximations. It is, however,
hardlv worth while to make elaborate calculations to find these

Fig. j.

pressures ; there are several examples of this type of arch with a
thickness of 6 inches at the crown in actual existence. If it is
desired to make a saving in material from that required by this
thickness, it will be better to depress the filling over the piers and
leave the crown thickness 6 inches. The arches of the Albany
filters were made with such a depression ; this is shown by the
dotted lines in Fig. 3. This depression was filled with clean gravel
and drained into the filter by pipes set in the piers. These pipes
are also shown by dotted lines in Fig. 3.

Where it is permissible to drain the water that seeps through
the earth covering, to the inside, this is in some respects better than
a flat surface ; some concrete is saved without weakening the arch,
and the drainage of the top of the vaulting is freer.

The amount of material in cubic yards in vaulting when con-
structed as shown in Fig. 3 is given in Diagram No. i. This is
designed to give the quantity within the inside lines of the side
walls for dift'erent dimensions of square and circular reservoirs

COVERED RESERVOIRS AND THEIR DESIGN.

(2| per cent, excess is allowed to cover variations). The cost per
cubic yard of concrete in the vaulting is probably no greater than
in other parts of the reservoir if the cost of the centering is not
included, but treated as a separate item. The cost of the centers,
their supports, placing and removing them, is from 15 to 20 cents
per square foot for the interior surface of the reservoir if it is all
centered at once. If it can be centered and covered in sections the
cost of centering will be greatly reduced.

EXCAVATION AND EMBANKMENT.

When it is possible to do so, as it usually is in a distributing
reservoir, economy demands that the material from the excavation
shall be approximately sufficient to make the embankment. For
ordinary conditions Fig. 4 shows a good design for the embank-
ment of either a square or circular reservoir, or for a filter that is
partially in embankment.

Fig. 4.

Diagram No. 2 gives the quantities of excavation and embank-
ment in square and circular reservoirs of different depths and
dimensions.

Trial computations to determine the elevation at which the
excavation will balance the embankment are usually tedious. A
few minutes' work with Diagram No. 2 will determine this so
nearly that one check computation will enable it to be fixed as
nearly as it is possible to do. If the site is level the results from
the diagram are correct ; if it is not level, take the average elevation
of the ground to be covered by the reservoir and its banks, and the
result will be approximately correct. One exact computation will
then show whether it should be raised or lowered a trifle. Ten
per cent, is allowed in the diagram for shrinkage. The method of
finding the elevation, or, in other words, the depth below the
average of the surface, that the bottom of the reservoir should be
placed is as follows: After the required horizontal dimension and

i6 ASSOCIATION OF ENGINEERING SOCIETIES.

total depth are determined, find on the lines of the diagram, which
represent the diameter of a round reservoir, or the length of side
of a square one, a depth of excavation and a height of embankment
that both fall upon the same horizontal line representing quantity
in cubic yards, and together equal the total depth of the reservoir
from the floor to the water line. Note. — When reading quantities
in excavation the scale for diameter or length of side must be read
at the bottom of the diagram, this scale reading from right to left;
while the dimensions must be read at the top when quantities in
embankment are required, this scale reading from left to right.

Generally more than one trial will be necessary to find a depth
of excavation and height of embankment the sum of which will
just equal the total depth of the reservoir, somewhat as follows:
If a proposed circular reservoir is to be lOO feet in diameter and 15
feet deep, assume for first trial that the depth of excavation will be
8 feet. Then on the diagram at the left, for round reservoirs, find
the intersection of line for 8 feet depth with that of 100 feet
diameter; read on the bottom scale. At this intersection the hori-
zontal line has a value of 2960 cubic yards. Following this
line across to the line for 100 feet diameter on scale for embank-
ment, read at the top, we find that value of the curve for embank-
ment intersecting at this point is 6 feet below the water line.
Therefore, the total depth of a reservoir that an excavation of 8
feet would provide embankment for is 8 plus 6, or 14 feet ; but the
required depth is 15 feet, and another trial must be made. Less
than I foot must be added to the 8 feet of the first trial. Trying 8.6
feet as nearly as it can be read, following the same process as
before, we find 3160 yards of excavation and a trifie less than 6.5
feet for the embankment below the water line, making a total of
practically 15 feet. Owing to the uncertainty in the actual shrink-
age of any soil, a determination within one- or two-tenths of a
foot is near enough for practical purposes. The actual amount of
the embankment measured in place will, of course, be only 90 per
cent, of that read from the diagram, as that includes the. 10 per
cent, for shrinkage.

N. B. — Depth of reservoir or "depth" when used in the dia-
gram always means the depth of water from floor to high water
line.

If the reservoir is located in a hollow, the excavation will be
some less than the diagram gives, using the average elevation of
the ground. If on a knoll, and probably if on a slope, it will be
more. A trial location by the diagram and one check computation
will enable the elevation to be fixed. If the reservoir is wholly in

COVERED RESERVOIRS AND THEIR DESIGN.

17

excavation, the amount will be found on the diagram by using the
depth from the surface to the inside bottom of the reservoir.

SIDE WALLS.

The side walls should be vertical, or nearly so, in order that
the vaulting shall have to cover as little area as possible. The
ordinary practice in the design of dams or retaining walls is not
applicable to these walls. Being supported outside by the earth,
they are not like a masonry dam. The thrust of the vaulting
resists the tendency of the wall to rotate on its toe ; therefore they
are unlike retaining walls. If the masonry were homogeneous, the
wall of a square or rectangular reservoir would act as a beam, with
the roof and floor as supports ; but it is improbable that the bond-
ing of the horizontal joints would be sufficiently good to prevent

IMT OF K«AX. MO

Fig. s.

failure. When, however, the point of failure is reached, in order
for it to proceed a crack or joint must open on the inside of the
wall. If the material is assumed to be rigid, either the part of the
wall above the break and the load upon it must be raised or the
lower portion must be pressed into the earth with a force equal to
the load above to allow the crack to open. In this case the moment
of the external forces acting upon the wall is resisted by that of the
weight into its lever arm.

An examination of Fig. 5 makes it evident that the whole wall
must be raised, but, as one edge is supported, only one-half of its
weight resists forces tending to lift it ; the weight of the half-arch
of the roof with its load must also be raised. If it is assumed that

i8

ASSOCIATION OF ENGINEERING SOCIETIES.

the material is not rigid, but will be crushed or tend to be crushed
on the edges on which the two parts rotate, the weight must still
be raised; but the lever arm of the weight will be shortened by so
much of the thickness of the wall as will sustain the weight above
the break without exceeding the strength of the material. In a
reservoir that is to be emptied occasionally, the maximum outside
pressure on the wall would be that due to water remaining in the
earth behind the walls. With a reservoir partly in excavation the
height of this water could not exceed the high-water line of that
inside, while in one wholly underground it might be at the surface,
or even above it, if the site were occasionally flowed. The maxi-
mum moment of this pressure, assuming that the water outside is

F»OINT OF M_AX.

Fig. 6.

at the spring line of the roof arches, is at one-third of the height
of the wall from the bottom ; its amount in foot-pounds is that due
to a load distributed in the form of a triangle, whose base is equal
to the height of the ;vall and whose perpendicular is equal to the
height in feet into the weight of water per cubic foot.

The foregoing refers to straight walls only; in the walls of
round reservoirs the outside pressure is resisted by the wall as an
arch. If this pressure is assumed to be due to the water in the
earth backing, it will be uniform all around, and the maximum pres-
sure at any point will not exceed one-half the product of the unit
pressure by the diameter. The total pressure will increase with the
depth and the diameter until dimensions are reached for which the
thickness must equal that for straight walls. For greater dimen-

COVERED RESERVOIRS AND THEIR DESIGN. 19

sions they must be designed to meet the conditions of the latter.
The thickness of the top of the wall is not governed by these con-
siderations. The thrust of the roof will largely determine this
thickness. On straight walls, as shown in Fig. 6, the horizontal
thrust of the roof is approximately 2.25 tons per lineal foot. Neg-
lecting the adhesion of the mortar, there are two factors of resist-
ance to this thrust, — that caused by the friction of the wall and its
load on any joint or place in the wall where movement would take
place, and that due to the embankment above such joint. With a
thickness at the spring line of 2^ feet, as shown in Fig. 6, the sum
of these two elements of resistance, above a point in the wall where
the resultant pressure of the arch and the wall above this point
passes through the outside of the middle third, is about 1.9 times as
great as the horizontal thrust of the roof, or a factor of safety of
nearly two.

With circular walls in which the groined arch must be carried
out to the wall at most points and can be at all, the average horizon-
tal thrust is not so great as in straight ones, being about 1.75 tons
per lineal foot. The resistance of the embankment above the
spring line is about 2 tons, or 1.15 times the thrust. It is easy to
increase this resistance by a ring of steel imbedded in the wall above
the spring line ; therefore it is not necessary to thicken the wall, as
the roof exerts only a vertical pressure upon it. Its thickness will
then be determined by the requirements of practical construction ;
all of these will be met by a thickness of 2 feet at the spring line.

As examples of existing walls with this type of roof, the two
following are straight walls. Those of the filter beds at Ash-
land, Wis., are 2 feet thick at the top, and have a batter of about i
in 10. These are either wholly in excavation or have an embank-
ment 15 feet wide, .supported by a braced pile trestle. The walls
of the Albany filters are in embankment, are 2^ feet at the top and
have a batter of i in 10. For circular walls, those of the Wellesley
reservoir are 2 feet thick at the top. The walls of the sewage reser-
voir at Clinton are to be 2 feet at the top and have a batter of i
in 10.

A steel ring was imbedded in the walls of the two last-named
reservoirs. In the Wellesley reservoir, which was 82 feet in
diameter, this ring was made of a channel iron weighing 32 pounds
per foot. In the one at Clinton it is to be in three parts or rings
of flat iron. The reservoir is 100 feet in diameter, and the total
weight of the rings per lineal foot is 30 pounds. This seems to be
a better arrangement of the steel than the channel iron, as the
joints or splices in the different rings can be "staggered" and loss

20 ASSOCIATION OF ENGINEERING SOCIETIES.

of streng-th in the total section reduced to that in one ring, and it
can probably be furnished and placed at a lower rate per pound.
Fig. 7 shows the arrangement of such rings in the section of
the wall. The following table gives the required weight for reser-
voirs of various diameters per lineal foot and the total weight.
The weights given are designed to provide a factor of safety of
three in the resistance to the thrust of the vaulting, including the
resistance of the earth embankment. Note. — In computing the
resistance of the embankment and the wall to sliding a co-efftcient
of friction of 0.80 was taken for earth ; of 0.65 for masonry. The
weights of the following table are also given on Diagram No. i,
which will give other diameters than those in the table:

Table No. 3.
Weight of Steel Ring.

Diameter in Weight in Lbs., Total Weight

Feet. per Lineal Foot. in Lbs.

50 14-5 2,280

60 17.4 3,280

70 20.3 4,460

80 23.3 6,850

90 26.2 7,380

100 29. 9,120

125 36-3 14,300

150 43-5 20,600

175 50.8 28,000

200 58. 36,500

Formula for dimensions not in table: Weight per lineal foot == 0.29
Diam. Total weight = 0.912 Diam.'

In the above table 25 per cent, is allowed for splicing and
rivets ; therefore, to find the weight of the net cross-section take 80
per cent, of the above weights per lineal foot.

In the construction of the walls satisfactory results can be
secured by the use of either concrete or rubble masonry of sound
angular stones of any sizes that are not large enough to go entirely
through the wall. Exceedingly good work can be done with small
stones by laying the face of the wall up to a form and bedding the
stone thoroughly in the mortar without regard to bonding, making
a coarse concrete in fact. All smooth, rounded stones should either
be broken or thrown out. Portland cement should be used for
this work, as it should be for all of the work in these reservoirs.
Natural cement may, of course, be used, but as strength is required
rather than weight the cost of equally satisfactory work will be
greater than with Portland cement. The choice of concrete or
rubble will probably depend upon the kind of material which is
the most available.

COVERED RESERVOIRS AND THEIR DESIGN. 21

Diagram No. 3 gives the amount of masonry in the side walls
of square and round reservoirs. This diagram is computed from
the sections shown in Figs. 6 and 7, and includes all of the masonry
from the under side of the foundation to the extreme top of the
wall. "Depth," as before, means depth of water. These sections
are sufficient for reservoirs of the dimensions given on the diagram,
and are uniform for all. They could perhaps be made lighter for
the smaller sizes and depths of the round reservoirs if it was con-
sidered desirable to do so. For preliminary estimates it is hardly
worth while to make any changes from the quantities given on the
diagrams. The following tables give the approximate unit pres-
sures that the maximum outside pressures bring upon the masonry
when calculated in the manner already indicated :

Table

No. 4.

Straight

Walls.

Height of
Wall.

Maximum
Moment.

Necessary
Weight of Length
Wall to be of Lever
Raised. Arm.

Thickness

of Wall at

Point of

Max. Moment.

Thickness
Remaining
to Resist
Crushing.

Total
Pressure

on
Masonry.

Max. Unit

Press. Tons

per

Sq. Ft.

Col. I

2

3

4-1

5

6=f

7

8=^

5 feet. .

.. 0.180

2.62

0.07

2.80

2.73

2.40

0.88

10 " . .

. . 1.50

3-24

0.47

3.20

2.73

2.80

1.03

IS " ••
20 " . .

.. 478
. . 11.25

4.10
4.80

1. 17
2.35

. 3-50
3.80

2.33
1-45

3.20
3.80

1.38
2.62

25 " ..

. 22.00

560

3-93

4.20

0.27

4-30

16.00

Diameter.

Col. I
50...

75-. •
100. . .
125...
150...
200. . .

Table No. 5.
Circular Walls at Depth of 25 Feet.

Total Pressures

Cross-Section

Maximum

at Bottom on

in

Unit Pressure

Section One

Square

per

Foot High.

Feet.

Square Foot.

2

3

4=1

19.5 tons

4-50

4.33 tons

29.6 "

4.50

6.57 "

3905 "

4-50

8.67 "

48.80 "

4.50

10.8s "

58.50 "

450

13.00 "

78.00 "

4-50

17-35 "

Although the extreme pressures in the tables may be considered
rather high for rubble and concrete, it must be remembered that
they could only occur if the water in the earth backing remains at
the high-water line until the reservoir is wholly emptied. This
would be a rare condition in an embankment, and may be avoided
entirely if desired. The method of doing this will be referred to
hereafter.

The pressure of the water in the reservoir tending to force the
wall outward must be resisted by the earth backing, otherwise the
wall must be designed as a dam. If this were necessary, all of such

22 ASSOCIATION OF ENGINEERING SOCIETIES.

walls that are existing to-day would have failed. If there is a
slight yielding in the earth, it is probably compensated by some
elasticity in the masonry. It is of the utmost importance, however,
that the backing be deposited in very thin layers and thoroughly
rammed. If the nature of the excavation is such that it will stand
vertically or nearly so until the wall can be built, it is desirable to
make the lower part of the latter without batter or offset on the
outside to as high a point as possible and to lay the masonry
solidly against the undisturbed earth. If the theory of the resist-
ance of straight walls that is adopted in this paper is correct, they
may be built with a vertical back from the point of maximum
moment (at one-third of their height) to the bottom without loss

SPRING I.INC

Fig. 7.

of strength. Fig. 4 shows how circular walls may be built to
secure a vertical line in the lower part of the wall ; there will gener-
ally be no objection to the interior offsets, and in filters they are
desirable in order to avoid a direct line for the water to follow
from top to bottom.

There is one more factor to be considered in the design of
straight walls; that is the tendency of the wall to slide into the
reservoir. Following the idea that the wall is a loaded beam, the
tendency to slide must be met by a reaction at the top equal to
one-third of the total load on the wall, and at the bottom to two-
thirds. Assuming water pressure at the back as before, the loads
and reactions are as follows :

COVERED RESERVOIRS AND THEIR DESIGN. 23

Table No. 6.
Reactions at Top and Bottom of Straight Walls.

Height of Wall. Total Load. Reaction at Top. Reaction at Bottom.

5 feet 0.39 tons 0.13 tons 0.26 tons

10 " 1.56 " 0.52 " 1.04 "

15 " 3-50 " 1. 17 " 2.33 "

20 " 6.23 " 2.08 " 4.15 "

25 " 975 " 3-25 " 6.50 "

There are three factors of resistance to shding at the bottom of
a wall such as shown in Fig, 6, — the friction of the wall on the
earth, the resistance to compression of the concrete floor and of the
earth inside of the foundation under the floor. With a floor 4
inches thick and wall foundation 6 inches deep, with co-eflicient of
friction of the wall on the earth of 0.65 and safe pressures on the
earth and floor concrete of 2^ and 10 tons per square foot, respec-
tively, the total resistance for a unit section i foot long is given in
Table No. 7 :

Table No. 7.
Resistance to Sliding of the Bottom of Straight Walls.

Height Friction Resistance Resistance Total Reaction E.\cess of

of 'WaU, on Earth. of Concrete. of Earth. Resistance. at Bottom. Resistance.

Sfeet 1.76 3.33 1.25 6.34 0.26 6.08 tons =

10 " 2.27 Z.Z3 I.2S 6.85 1.04 5.81 "

15 " 3-05 2-33 1-25 7-^3 2.33 5.30 "

20 " 3-83 3-33 I-25 8.41 4.16 4.2s "

25 " 4.62 2.32, 1.25 9-20 6.50 2.70 "

These figures indicate that such walls under 25 feet in height
will not fail by sliding at the bottom. They will not fail at the top
if the thickness is sufficient to prevent shearing. The reaction at
the top of a 25-foot wall is 3.25 tons. The section to be sheared in
a wall 2^ feet thick at the top is 360 square inches per lineal foot,
or a stress of about 19 pounds per square inch. There are no data
on the shearing strength of concrete; it seems, however, that it
must be greater than the tensile strength, and that the above must
be a safe figure for that of good concrete or rubble in Portland
cement. The above stresses only occur in a reservoir that is just
emptied.

Note. — As the thrust of the vaulting against the wall in the
proposed design is but 2.25 tons per lineal foot, if the required
reaction at the top must exceed that amount in order to resist the
outside pressure, the load on the vaulting must be made heavier
and the vaulting stronger to provide the required reaction.

PIERS AND THEIR FOUNDATIONS.

The maximum load upon each pier with the roof shown in
Fig. 3 is about 46 tons, the piers being 14 feet apart on centers in

24 ASSOCIATION OF ENGINEERING SOCIETIES.

each direction. Piers can be built of either brick or concrete. The
great majority of existing piers are of brick, very few of con-
crete being on record. There seem to be practical reasons for the
use of brick. The amount of material is not large, and it is prob-
able that the expense of making and setting forms for concrete will
make its cost as great in this class of work.

The allowable unit pressure for Portland cement brickwork
is not definitely determined. Baker, in his book on "Masonry Con-
struction," gives about 30 tons per square foot as a general estimate.
In a pier, however, the relative dimensions should be considered in
its design. There is a wide diversity in practice, as shown by
existing examples. The following table gives the dimensions and
unit pressures in several modern reservoirs :

Table No. 8.
Dimensions and Pressures on Piers.

Unit

, Piers , , Roof Surface , Treasure

Section, Cross-Section Area, Approx. Unit Multiplied

Height, Square Divided bj Square Weight, Pressure, by Length

Reservoir. Feet. Feet. the Height. Feet. Tons. Tons. of Pier.

Newton 13.5 2.78 0.205 136 Z2. 11.5 155

Brookline 17.5 4.00 .228 144 26.5 6.63 116

Franklin 16.5 i.oo .061 90.5 20 20 330

Ashland 5.0 4.00 .80 248 54 13.5 67.5

Wellesley 12.25 40O .325 196 51 12.75 156

Albany 7.5 2.78 .370 187 41 14.75 III

Clinton 7.0 , 4.00 .572 210 78 19.5 136

Proposed 7.0 2.78 .398 196 46 16.55 116

The height of piers given in the above table is not in every
case the total height from the floor to the spring line, but the length
between offsets. The piers in the first three cases had no offsets,
but were uniform in size from top to bottom; in all of the others
the bases of the piers were enlarged, and in the Clinton reservoir
and the proposed design the top is also enlarged by offsets. It is
very desirable to spread the base in order to distribute the strains
over as large an area of the top of the foundation as possible, so
that it may be made thinner and still not overload the earth below.
Where the unit pressures are high it is also desirable to spread the
top of the piers, so that they may not be so great m the concrete
at the spring line. A neat and economical design for piers is to
make the body of the same size for all heights, and make the offset
portion at the bottom (and at the top if desirable) longer as
the total length of the pier increases, keeping the length of the body
the same for all heights of reservoir.

Fig. 8 shows a pier of this design. The body of the pier is 20
inches square, and for heights of 8.25 feet and over its length is
7 feet. The base increases in height, but not in bottom area, as the

COVERED RESERVOIRS AND THEIR DESIGN. 25

pier is made longer. Diagram No. 4 gives the amount of brick-
work in such piers for different sizes of round and square reser-
voirs. These quantities are based upon the areas of the reservoirs,
and are not precisely correct for some dimensions, but are nearly
enough so for preliminary estimates. The following table gives
the exact amount for one pier, and, if closer results are desired than
the diagram gives, the exact number of piers can be obtained from
a plan and the quantities from the table used :

Table No. 9.

Brickzvork in Piers of Various Heights from Floor to Water Line.

Note. — This height is i foot greater than the actual length of
the pier.

Height of Brickwork, Height of Brickwork, Height of Brickwork,

Reservoir. Cubic V'ds. Reservoir. Cubic Yds. Reservoir. Cubic Yds.

5 feet 0.62 12 feet 1.62 19 feet 3.01

6

9
10
II

0.62

12

.72

1.3

.«3

14

•95

15

1. 10

16

1.27

17

1-45

18

I

82

20

2

■03

21

2

.24

22

2

AS

2?,

2

64

24

2

83

25

3-20

3-40
3.60
379
3.98

4-17

Piers should be built of the best of brick, in respect to the
qualities of hardness, homogeneity and uniformity of shape and
dimensions. They should be laid with absolutely full joints in
Portland cement mortar as closely as the brick can be laid and the
joints neatly struck with a jointing tool.

PIER FOUNDATIONS.

Pier foundations should be designed to transmit the pressure
from the piers to the earth uniformly, with a unit pressure that is
safe for the character of the ground. The following table is taken
from Baker's ''Masonry Construction" :

Table No. 10.
Safe Bearing Pozuer of Soils.

Tons per Sq. Ft.
Kind of Material. Minimum. Maximum.

Clay in thick beds, always dry 4 6

Clay in thick beds, moderately dry 2 4

Clay soft I 2

Gravel and coarse sand, well cemented 8 10

Sand, compact and well cemented 4 6

Sand, clean and dry 2 4

Quicksand, alluvial soils, etc 0.5 i

The soil in most sites of reservoirs for water supplies would be
as strong as sand, compact and well cemented, and could be loaded
with 4 tons per foot. Sewage reservoirs and filter beds might often

26

ASSOCIATION OF ENGINEERING SOCIETIES.

be on less secure foundation. Each case must be considered on
its merits. Having determined the horizontal dimensions by
reference to the allowable unit pressure on the soil, the depth or
thickness of the foundation depends upon its size and that of the
bottom of the pier that rests upon it. The thickness will probably
be sufficient if a line drawn from the outside edge of the bottom of
the pier to the bottom edge of the foundation has a batter of not
more than i to 2 ; thus, if the foundation is 6 inches larger each way
than the bottom of the pier, its thickness should be not less than i
foot. With good Portland cement concrete this would distribute
the pressure over the entire bottom of the foundation. From
Diagram No. i the quantities may be taken for the pier foundations

|<-3'-6- >i>

Fig. 8.

shown in Fig. 8, which were designed on the foregoing principles
to carry the roof and the load that has been described. The esti-
mated pressure on the soil in this case is about 3.8 tons.

FLOOR.

There should be a smooth concrete floor in all covered reser-
voirs. Its thickness is dependent upon the conditions of the par-
ticular reservoir. If the material in which it is built is such that
there is little danger of outward leakage, and there is no likelihood
of an upward water pressure to lift the floor when the reservoir is
emptied, a thickness of 3 or 4 inches is sufficient. The reservoirs
at Brookline, Newton and Wellesley had floors 4 inches thick; the
floor of the Ashland filter was 3 inches. If, on the contrary, the

COVERED RESERVOIRS AND THEIR DESIGN. 27

earth is pervious, and the movement of water when the reservoir is
full will be away from it, the floor should be at least 6 inches.
From his experience in the construction of and subsequent obser-
vation of a number of open reservoirs, also from experiments on
concrete of different thicknesses, the writer believes that with heads
of 20 feet and under 6 inches of good Portland cement concrete is,
or becomes in a short time, very effective in preventing seepage.
It should be plastered or finished with rich cement mortar. An
excellent method for floors is to finish the concrete as soon as it
is rammed, before it begins to set, with mortar mixed for the pur-
pose. If a surplus of water stands on the concrete after ramming,
good work can be done by spreading dry cement on and working
it to a smooth, close surface with trowels. The liability of separa-
tion and peeling off which exists in plastering that has been done
after the concrete has set is thus avoided.

If, when the reservoir is emptied, there will be an upward pres-
sure on the floor, it must be designed to resist it. For this pur-
pose inverted arches may be used, designed to carry the estimated
pressure to the piers. The roof arches may be reversed, or the feet
of the piers given a greater spread and flat circular arches
used. In designing to resist the upward pressure care must be
taken that the weight of the reservoir and its earth covering is
greater than that of the water displaced, to avoid flotation when it
is empty.

The Clinton reservoir is designed to resist this tendency to
float, as it is anticipated that at certain seasons the outside water
will stand above the reservoir and its earth covering. The latter
is made 4^ feet thick to provide the necessary weight. The floor
is a series of inverted arches. Where there is no sanitary objection,
drainage can be arranged in such a way that there will be no
upward pressure when the reservoir is drawn down. With a thin
layer of clean gravel or broken stone, and underdrains if necessary,
the water under the floor can be collected in a well, and through a
pipe tightly set in the concrete floor be delivered into the reservoir
when the pressure in the latter is less than that outside. An inward
opening flap or check valve must be placed upon the pipe to pre-
vent a loss of water from the reservoir. If drains were carried up
the back of the wall, the pressure on the latter would also be
relieved.

This arrangement would be undesirable in a sewage or other
reservoir, the contents of which must be pumped or treated, as the
amount would be increased bv a flow from the outside.

28 ASSOCIATION OF ENGINEERING SOCIETIES. •

PLASTERING.

To prevent leakage from the reservoir, and to secure a smooth
surface that will be easy to clean, the inner face of the side walls
should be plastered. The best results can be had with two coats,
one of mortar, 2 parts sand to i of cement, laid on as thick as it
will stay to even up the inequalities of the wall. This coat should
not be smoothed. The last coat to be of neat cement ^ to ^ inch
thick, thoroughly rubbed on with a trowel and nicely smoothed. If
there is an outside pressure from water in the ground, it must be
reduced by pumping during the plastering and until it is set.
Under such conditions the outside should be plastered, if for any
reason it is desirable to permanently exclude the ground water.

Diagram No. 5 gives the number of square yards of the
plastering on the walls of reservoirs of different dimensions. The
depths for which the diagram is figured is that from the floor to
the high-water line.

MISCELLANEOUS ITEMS.

There are a number of items that will vary in different reser-
voirs. Among these are the piping, gates, manholes, ventilators,
ladders and, if an automatic recording gauge is used, a small build-
ing and the apparatus itself. The cost of these items will be from
7 to 12 per cent, of the total. Seeding and sodding the top and
slopes are included in the above.

TOTAL COST OF RESERVOIRS.

On the diagrams that accompany this paper are given the quan-
tities of the material in the different parts of the reservoirs of the
type described in the paper and shown on the sketches. With
some of them there is a multiplying diagram by which the cost of
such quantities at various prices per unit may be found. With the
diagrams an estimate of the quantity of material and the cost of a
reservoir of any dimensions within the limits of the diagrams can
be readily made that will be correct for this type. A slight change
in design, as, for instance, different spacing of the piers or minor
changes in the form of the parts, will not materially affect the
estimate.

For making preliminary estimates with even less work than
the above entails, and for rapidly determining the economic ratio of
depth to area for any desired capacity. Diagram No. 6 has been
prepared for round reservoirs and No. 7 for square ones. These
diagrams give the capacities in gallons and the cost in dollars for
all of the dimensions within their limits. They were prepared by

COVERED RESERVOIRS AND THEIR DESIGN. 29

taking the sum of the cost of all of the items at the unit prices given
in Table No. 11, and adding 10 per cent, to this sum for the miscel-
laneous items. The value of this diagram in finding the economic
ratio of depth to horizontal dimensions is not limited to this type,
as this ratio will be approximately the same for others. It is
beHeved that it will be found useful in preliminary estimates for
other types and at other unit prices by applying such corrections as
the engineer believes to be necessary.

Table No. ii.
Unit Prices of Quantities in Covered Reservoirs.

Earth excavation per cubic yard $0.50

Rubble or concrete in walls, pier foundations and floors " "■ " 6.00

Concrete in roof " " " 6.50

Brickwork in piers " " "• 13.00

Plastering walls " square " .25

Plastering floor " " " .15

Gravel on roof arches " cubic " i.oo

Steel ring per pound in place .05

Centers, etc per square foot for total area of reservoir .15

Table No. 12 gives the cost of certain capacities of reservoirs
w^hen built with economic dimensions. Caution. — As prices have
risen materially since Diagrams 6 and 7 were prepared, it is prob-
able that a percentage should be added to the results for present
use.

It is perhaps needless to caution the reader against using the
designs or the quantities given in the paper unless the conditions
are substantially similar to those described, or until proper modi-
fications are made.

Table No. 12.
Cost of Covered Reservoirs zvhen Built zvith Economic Dimensions.

Taken from Diagrams 6 and 7.
Capacity. Round Resenoirs. Square Reservoirs.

Gallons. Diam. Depth. Cost. Diam. Depth. Cost.

250,000 60 12 $4,700 54.5 II $4,800

500.000 75 16 7,800 69.5 14 8.100

750,000 88 17 10,500 79.5 16 11,000

1,000,000 98 18 12,850 88.5 17 13,550

1,250,000 106.5 19 15,200 99.5 17 16,050

1,500.000 115. 5 19 17.550 106 18 18,400

1,750,000 120 21 19.950 III-5 19 21,700

2,000.000 ..../.... 125 22 22,000 1 18.5 19 22,900

2,500,000 134 24 26,200 130 20 27,300

3,000,000 144 25 . 30,200 142.5 20 31.450

4,000,000 *i66 *25 37.900 153.5 23 39.500

5,000,000 *i86 *25 45.600 *i65 *25 47,400

*These are not the economic dimensions. The diagram does not give
greater depths than 25 feet. Moderate departures may be made from the
economic dimensions, in either direction, without greatly increasing the cost.

30

ASSOCIATION OF ENGINEERING SOCIETIES.

Depth.

Cost.

20.5

$37,600

19

17,550

18.5

17,600

II-5

19,900

Cost of 1,500,000 Capacity with Different Dimensions.

Gallons. Diatn.

1,500,000 112

1,500,000 * IIS-S

1,500,000 * 118 '

1,500,000 150

SECTIONAL RESERVOIR COVERING.

On account of the cost of centering for the type of vaulting
described in this paper, it has seemed to the writer that it would be
desirable if some form of vaulting could be devised in which this

re^'

Fig. 9.

cost can be reduced and the advantages of the groined arches
retained. The very successful use of a combination of steel and
concrete in floors that sustain heavy loads has suggested the adop-
tion of some such type of construction for covering reservoirs. It
is undesirable to use in this work steel that cannot be thoroughly
imbedded in concrete. For this reason, and because they will cost
more than masonry, it is not proposed to support the covering on
steel girders, as the floors are supported. It is proposed to build
brick piers spaced the same as for the groined arches, and from

CEMAr

noiaao RI3H'

i,,,-.*""

• I cj^f^s^ji^aijei.-

130 HauonH:

JOUR. ASS'N ENG. SOCS.

FREEMAN C. COFFIN-COVERED RESERVOIRS AND THEIR DESIGN.

■lv-^'^!;^*^^'!^'>>^fi^f*y^y?^^*r*?^yi|f^!l'?^i'^'ilPAqw^^P^

ELLE.SLEV w^TER WORKS

ADDITIONAL SUPPLY

PLAN OF 600000 GALLON COVERED RESERVOIR

ON Mauslp* Hill

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COVERED RESERVOIRS

BRICK f»ie:rs

COVERED RESERVOIRS

COST AND CAPACITY

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COVERED RESERVOIRS AND THEIR DESIGN. 31

these piers spring brick arches each way, as shown in Fig. 9.
These arches will support a slab of the steel-concrete, as shown in
the figure.

The advantages to be secured in the construction of this type
are that simple circular centers cari be used for the brick cross-
arches, and only enough of them will be necessary at one time to
build one line across the reservoir, as there is no diagonal thrust
caused by the arches. The centers, or rather forms for the cover-
ing slab, W'ill be simply a plain flat surface ; as many or as few of
them may be prepared as may be required for the proper rate of
prosecution of the work. The best of work can be secured in the
slabs, as they are made independently of each other and can be
finished before the concrete is set; therefore with a perfect bond
throughout.

This type of covering will give practically the same head room
and arrangement for ventilation as the groined arches, and will,
I believe, be cheaper and less troublesome to build. The thickness
shown in Fig. 9 is not to be assumed as correct. No computation
has yet been made to ascertain this correctly. One of the companies
that supply the metal for this construction, in answer to an
inquiry, stated that it was probable that under the named conditions
No. 4 gauge metal and 6 inches of concrete would carry 300
pounds per square foot, but advised the writer to make the computa-
tions himself. He had already found that the distinguished mathe-
matician St. Venant has said that the problem of the strength of a
square slab supported at its four edges is incapable of solution, and
has therefore not yet made the computation. Experiment is the
proper method of determining the safe thickness, and fortunately,
if it should be desirable to build this form, such experiments on
full-size test pieces in place could be readily made. Lacking such
knowledge, it has not seemed advisable to make any estimates of
the cost for comparison with that of other types.

32 ASSOCIATION OF ENGINEERING SOCIETIES.

L FIELD NOTES OF A CIVIL ENGLNEER.— DO THEY

BELONG TO HIS CLIENT OR TO HIMSELF ?

By J. Vander Hoek.

[Read at the regular monthly meeting of the Engineers' Society of Western
New York, Buffalo, N. Y., October 7, 1895.]

Mr. Chairman and Gentlemen : When I was asked by a
member of the Topic Committee of this Society to prepare a paper
on the question, whether the field notes of a civil engineer belong
to his client or to himself, I had never given this matter any serious
consideration. During the few years of my practical experience
in civil engineering in this country I have never been placed in a
position where it appeared to me that the private ownership of the
field notes which I took could be of any benefit to me. For this
reason I am not able to speak on this subject with the fuller knowl-
edge of one who has often been interested in this question and
whose opinion has been matured by the discussion of the various
features of cases which have presented themselves to him in prac-
tical life. I have, nevertheless, accepted the invitation and pre-
pared this paper, because I consider the topic well worthy of
attention, and also because it appears to me that this question may
perhaps be introduced with more freedom by a member who has
been placed thus far outside the general engineering practice and
who is not concerned, except in a general way, in the conclusion
of the argument.

It will not surprise you, after receiving this communication,
that I have been obliged to build up an opinion by considerations
of a theoretical rather than of a practical nature, and that I have
made use of actual and fancied cases only to make clear and to test
the correctness of the rulings.

Before entering upon this part, I wish first to say something
to define the word "field notes." Field notes may be said to refer
to all data that are taken in the field, for the purpose of describing
the conditions of the field, or of describing the location of objects
on the field. These data are noted down in books on the ground
and form what are commonly called "the original field notes."
Copies of these original field notes are sometimes prepared and
known as "copies of field notes." I intend to use these names in
this paper to distinguish their limited meaning from the more,
comprehensive sense of the word "field notes," which includes also
the information contained in these notes, — that is, the knowledge
of which the notes are the memoranda. While the original field

FIELD NOTES OF A CIVIL ENGINEER. 33

notes and copied field notes refer to books, the word "field notes,"
in its fullest sense, stands for the information itself and has an
abstract meaning.

I have made this distinction to show that while the original
field notes, being tangible objects, can as such be the subject of a
dispute of ownership in law, the information which they contain
is something too subtle to admit of the enforcement of court de-
cisions. For so far as the question refers to the note books, we
should go to the common law for advice, and so far it forms
more properly a topic in a lawyers' debating club than in an
engineers' society. But if we consider it with the word "field notes"
taken in its broader meaning, the issue cannot any more be decided
in the courts, and may best be discussed by members of our pro-
fession. I wish here to call attention to the fact that inasmuch
as the field notes are nothing else than the memoranda of certain
information, it must follow that the party who is found to be en-
titled to the ownership of this information is also entitled to the
possession of the notes.

In formulating the question, the word "client" has been used,
although this word, properly speaking, refers only to a person who
applies to a lawyer for legal advice. I suppose that the word client
has been preferred to the word employer in order to bar from the
discussion all such cases where the engineer is in the position of
a regular employe. Allow me, however, to consider also such
cases, because I think that there are many engagements which
place the engineer, although conducting a general practice, into
a position similar to that of an employe. Moreover, the relation
betv^-een the employer and the employe is a very simple one, and
the features thereof are well understood, so that a study of the
question under the conditions of this class affords the opportunity
to point out some fundamental principles.

I have found it most expedient to divide the cases of various
relationship which may exist between civil engineers and their
employers and clients into two classes, and to consider the ques-
tion under the different conditions of each class separately. The
particular feature of the first class is that the engineer is paid for
all he does, while in the cases of the second class the engineer is
not paid for his work, but for the product or result of his work.
In the first class he is paid by time, in the second by piece.

I wish now to consider our question under the conditions of
the first class; two typical cases have suggested themselves to me,
namely:

(i.) The engineer is a regular employe and receives a salary.

3

34 ASSOCIATION OF ENGINEERING SOCIETIES.

(2.) The engineer has a general practice and charges by
time.

Referring to the engineer as an employe, I would say that he
agrees to work steadily and exclusively for his employer, and to
devote all his time to his employer's interest. He cannot properly
work for another party without the consent of his employer. He
receives in compensation a regular salary, which he accepts in full
payment of all services rendered during the period of time for
which the salary is paid. Considering our question under these
circumstances, I would say that the common law governing the
ownership of the products of labor, performed by employes on
the time of their employer, does not leave room for any difference
of opinion as to whom the original field notes belong. I do not
think that there can be any dispute of this point, as whatever the
employe produces in the time of the employer is the property of
the employer. As to the right of employes to copy the notes in
their own time for their own benefit, I would say that they have no
such right, because the employer has not only paid for the work
of writing down the notes, but for the work of obtaining the in-
formation, and, therefore, this information itself properly belongs
to the employer as well as the notes.

However, the engineer does, as a matter of course, gain more
or less information while he is engaged in gathering the field notes,
whether he wishes or not; and while the employer may refuse his
employe the privilege of preparing copies of the notes, which he
has taken, for private use, he can certainly not take away from
him the knowledge which he has acquired. The question now
comes up whether an engineer working under such conditions has
a right to make notes from memory for private use.

I take leave to give in this connection a few lines taken from
the issue of Engineering Neivs, dated March 22, 1894:

"In a late issue of the Troy Polytechnic Prof. W. S. Raymond
answers another writer in the same journal, who, in the course of
a paper, noted that a certain civil engineer discharged his best
assistant for keeping a private note book. This engineer explained
his action on the ground that these notes of survey were the private
property of the chief ; that they were valuable to him as a guide in
making future surveys, and hence were decreased in value by
duplication. Mr. Raymond suggests the desirability of presenting
another side of the question, which, he believes, is more correct in
principle, as follows :

"Mr. Raymond believes the young assistant is entirely justified
in recalling at night the work of the day and in making notes of it.

FIELD NOTES OF A CIVIL ENGINEER. 35

He does not use his employer's time in field or office, and as he gains
in experience he becomes more valuable to his employer. In fact,
a part of his salary is this experience, which is practically the knowl-
edge he gains of certain methods and of the locality in which he
works. If he uses his employer's time, however, in making his
notes, he is obviously doing wrong, though he is following an
example constantly before him."

Allow me to say that in my opinion the side presented by
Mr. Raymond is not correct in principle. Although I gladly con-
cede the right of every man to prepare memoranda of his day's
work and of whatever appears of interest to him, I do not think
that he can consider the information so collected as his private
property. He should never lose sight of the fact that these memo-
randa were made while he was in a position of confidence, and that
he gathered the data while in the discharge of his professional
duties. Information obtained under such circumstances should
not be used without having due regards for the interest of the
party who paid for the work. From a practical standpoint no one
can dispute that this information belongs to him, but from a moral
standpoint I would say that it is not owned, but, so to say, held in
trust, by him.

I wish to give one example in support of what I have said
and to select a strong one in order to present the points at issue as
clearly as possible.

Suppose a railroad company employs a civil engineer for the
purpose of finding a route through a very difficult piece of country
and spends large sums of money in extensive surveying in order to
secure the very best location, or perhaps the only feasible one. A
second railroad company, as is not unfrequently the case in this
country, desires to construct a line through the same territory,
but has no surveyors in the field. Under such circumstances the
information gathered by this engineer is not only very valuable to
the first railroad company, but equally valuable to the second one.
The company who pays will therefore not only exercise its right
to the original field notes, but has good reason for refusing the
duplicating of the notes. It can, however, only protect itself for
so far as the actual notes are concerned. The engineer of the party
acquires after many surveys more or less complete knowledge of
the country examined, and can, without referring to note books,
point out to the second company the best or only feasible location.
Can he now consider this knowledge as his private property? If
so, he should have a right to do with it as he pleases. I do not
know whether the common law would stand in the way if this

36 ASSOCIATION OF ENGINEERING SOCIETIES.

engineer saw fit to offer his information for sale to the rival corn-
pan}', but all honest men will agree that in so disposing of his
private notes he would place himself on one line with a common
cheat. In this case we find that the engineer has no right to dis-
pose of this information, and for that reason it cannot be said to
be his property.

I will admit that in the general run of engineering work the
information collected during its consummation is not of much
benefit, except to the party who paid for it, and that, therefore,
the exclusive possession of it is not considered of importance.
Neither do I think it necessary for an employer to prohibit his
engineer to take copies of notes, except in special cases; but where
there is here a question of right to be answered, I would say that
the importance of the possible consequences does not alter the
principle involved.

The knowledge that comes to the engineer while doing work
for others becomes part of him in the same way as a lawyer be-
comes acquainted with the legal situation of his client, and as the
physician learns the physical infirmities of his patients. Neither
of them actually own this knowledge, and they are 'at liberty to
make use of the notes for such purposes only as are in the interest
of the client and the patient, or in the general interest of their
profession.

The large body of subordinate engineers who are employed
as assistants to chief engineers come under this class, and I sup-
pose that we all agree that a civil engineer, placed in such a posi-
tion, should be faithful and loyal to his superior, and that the chief
has a right to expect that his assistant shall treat as confidential all
important information that may come to him in the performance
of his duties. That, as a matter of fact, many employes do con-
sider information obtained during the work as their property is,
I suppose, due to a large extent to the neglect of their employer to
exercise his right. Sometimes the employe is allowed to consider
himself as the sole owner of the field notes by the lack of interest
taken by his employer, and this accounts for the strange notions
which are found in the heads of some employes.

I wish to cite here again from Engineering Nezus for an illus-
tration:

"As a case in point, though not exactly connected with the
class of employes here dealt with, the editor is reminded of a bit
of experience of a one-time chief of the water department of one
of our largest cities.

"This chief succeeded to an office practically devoid of all

FIELD NOTES OF A CIVIL ENGINEER. n

records of work performed, and he was forced to have complete
re-surveys made of the much scattered property, buildings, reser-
voirs, etc., under his control. The engineer charged with survey-
ing the reservoir finished the work above ground with little diffi-
culty, but there was a chain of reservoirs connected by a very
complicated system, of buried pipes and gates, and it was absolutely
necessary for the completeness of the work that this connecting
system should be accurately mapped. But here he met an obstacle
in the form of reservoir keepers, who had held their offices through-
out all changing administrations simply because they, and they
alone, knew where the pipes, gates and stops were located, and how
they were connected wdth the city system. These keepers positively
refused to give away this private information, and there was a halt
in the survey. The chief, however, was equal to the emergency,
and, sending for the keeper of one of the smallest reservoirs, he
personally requested that he point out to his engineers all this
underground plant. The keeper again refused to comply, and,
somewhat to his surprise, he was discharged upon the spot. The
next morning a gang of laborers appeared at the reservoir, formerly
in charge of this keeper, and a trench was cut clear around it ; every
pipe was uncovered and followed to its connection or stop, and a
complete survey was then made and mapped. It is hardly neces-
sary to state that there was a sudden change of heart among the
other keepers, and the engineer in charge of surveys had little
further trouble in getting all the information he needed."

It seems to me that the blame in this example rests more with
the engineers who constructed the water works than with the gate
keepers; and it has been given for the purpose of showing with
what undesirable results the employer might be confronted if he
should have to depend upon employes who consider as private
property the knowledge which they gain in the discharge of their
duties.

I now wish to consider other cases of this same class, but of
the second type, which refers to engineers who are not in the
position of an employe, but are conducting a general practice.
They render services and do work for various parties who call
upon them for that purpose, and charge their employers or clients
fees, dependent upon the amount of labor involved, or on the im-
portance of the services rendered. Although there may exist an
understanding as to the amount of the fee, per day or per hour of
labor, there is no agreement as to the amount of the final bill. In
other words, the engineer, to use a contractor's expression, charges
for the work bv force accot:nt. I would sav that althousfh the verv

38 ASSOCIATION OF ENGINEERING SOCIETIES.

highest kind of engineering services belong to this group, from a
legal standpoint the conditions existing here are very much the
same as those under which a regular employe is engaged. It is
true the engineer is not expected to devote all his time to the
work of this one client; a man in general practice is understood
to divide his attention between several matters. But the important
point which, I think, rules here is that the agreement provides that
the client shall pay for all the time and labor involved and, for
that reason, is entitled to all the results of the work. The engineer
employed in this manner is only in so far differently situated from
a regular employe that he is in a larger measure independent, but
this does not confer any more rights to the results of his work
than a permanent employe has.

I can readily see that in actual life the engineer keeps the field
notes, guided by the idea that they are more valuable to him than
to the client, and also because he feels that he will take better
care of them than the client himself. Moreover, the field notes
of one piece of work may be very helpful in the study of another
one in the same neighborhood, and in this way do increased ser-
vice. But these considerations are all based on convenience, and
do not establish any owner's rights. If the client does not claim
the field notes, all is good and well, but in case he insists upon
having them, I think that justice and the law are on his side.

Suppose, for instance, that the engineer, who has entered into
an engagement of this type, should die while the work is in prog-
ress, and that already a large amount of field notes have been
collected, the possession of which is necessary for carrying on the
work. I do not doubt but that we all agree that, under such cir-
cumstances, the client should have the right to take possession of
the notes upon payment of their cost. Yet the death of the engi-
neer does not in any way diminish his rights, and if the notes prop-
erly belonged to him while alive they could not have been claimed
by the client after his death.

There are a good many other cases where the field notes are
very valuable to the client. I give below a few instances which
cover the most important conditions:

Whenever an engineer is called upon to make a survey for a
map which is to be on a small scale, as, for instance, a topographi-
cal map of a section of the country, he is unable to make his map
show all the details as clearly and precisely as the field notes will
afford. Generally speaking, the precision of a survey should not
be any greater than required for the accurate mapping to a given
scale, but in many cases it is more convenient to measure the

FIELD NOTES OF A CIVIL ENGINEER. 39

topography with greater precision than can be represented on the
map.

The field notes have, on account of this additional information,
considerable value. Besides, the notes are absolutely necessary
when the time comes for making alterations to and corrections on
the map. It seems evident that the client who pays the engineer
for making such a map should receive all the field notes with the
map.

I wish also to call your attention to surveys of lines and
objects which are subject to changes by natural forces and where
it may be important to use the field notes for precise relocation of
objects afterwards.

For instance, in all cases where improvements are proposed
which may interfere with the flow of water in rivers and streams,
or change the stage of water, etc., a complete set of field notes is
very important to the client, because in after times some one may
come to the front with a claim for damages alleged to have been
caused by the works. The original field notes will then give
evidence as to the situation before the improvements were carried
out.

A very common case where field notes are of the greatest im-
portance to the client is when they refer to contract work and are
to be used for calculating the quantities which are to form the
basis of settlement between the contractor and the client.

Last, not least, I would call attention to those cases where an
engineer has charge of the engineering in relation to municipal
improvements, w'hich require for their maintenance a full knowl-
edge of their construction. I wish here to refer especially to sew-
erage systems, water works plants, laying out and grading of streets.
Although from a legal standpoint it seems to need no argument
that an engineer engaged upon such work and charging his client
for all the work that he has done has no right to the field notes,
yet it is not a difficult matter to cite cases w^here the engineer has
claimed all the notes as his own.

I will cite here one case given in an editorial of Engineering
N^ezi's, dated July 14, 1892, in the form of an answer received from
a city engineer in response to a request for information regarding
the sewerage system of a city with more than 30,000 inhabitants,
which is as follows :

'T am unable at present to fill up the blank you sent me. I
have been in this office only one year, and my predecessor has been
here twenty-six years. When he left he claimed the few records he
had kept as his own, and he left me very little more than the bare

40 ASSOCIATION OF ENGINEERING SOCIETIES.

walls of the office. He has a book containing the record of sewers
now in use, which he offered to sell to the city, but the Council
refused to buy, as they feel it should belong to the city by right.
I think they will soon decide that the cheapest way to get it will
be to buy it, and I will then let you know what it contains. As
there were no records or notes of any kind in the office, except a
record of street grades, I have not been able to make much headway
during the year. I hope to get affairs in shape soon so that the
records from this office can take their place with those of any other
well-conducted office."

It is apparent that the law does not make itself felt strong
enough to impress everybody with the necessity to keep on the
right side of it. I have not been able to find any legal decisions
directly bearing on this question. This. I think, is more due to
the fact that most clients have no adequate idea of the importance
of the notes, and consequently do not care about them when it is
the proper time to ask for them, than because there is no law to
sustain their rights. However this may be, there is in addition to
the written law of the land an unwritten one of honor, of which
no engineer can afford to disregard the precepts if he desires to
practice successfully in his profession. The relation of the engi-
neer to his client, especially where the engineer is invested with
the authority to use his own judgment as to the amount of work
necessary for the successful completion of the work on hand and
where he charges accordingly, he occupies a position of great con-
fidence and responsibility, and he cannot be said to serve his clients
well if he does not supply them with all the data and information
that may have to be referred to afterwards for the operation or in
the maintenance of the completed work. The engineer should
assume somewhat the same relation to the client as an attorney,
and take full charge of the client's interests as if they were his own,
and if the client is not able to appreciate whether the services
rendered are more or less complete, the engineer should feel an
increased necessity of protecting his client and not take advantage
of his inexperience.

It is proper in this connection to quote from the address which
Mr. S. Whinery, M. Am. Soc. C. E., former President of the Cin-
cinnati Engineers' Club, delivered at the annual meeting of De-
cember 15. 1892.

Speaking of the engineer's duty to his client relative to chief
engineers reporting directly to corporations or those engineers
who have a general engineering practice and who charge their
clients fees dependent upon the labor involved or the importance
of the services rendered, Mr. Whinery says:

FIELD NOTES OF A CIVIL ENGINEER. 41

■"When an engineer undertakes to do certain professional
work for a client or employer, it is obviously his duty to devote
himself to the interests of that client with conscientious zeal and
fidelity. His personal interests or affairs cannot be allowed to
stand in the way of loyal devotion to the interests of his client.
The only exception to this rule is where the demands or the interests
of the client conflict with the engineer's sense of right and wrong."

Basing himself on this principle, Mr. Whinery gives the fol-
lowing answer to this question: To what extent do the facts ac-
quired and the results reached in professional work belong to the
client for whom the work is done and to what extent do they be-
come the property of, or can they be made use of by, the engineer?
The answer is :

'Tt would seem clear without argument that all the original
notes, maps or plans and information, as well as the final result or
report, are the property of the client, who pays for having the work
done, unless there is a previous understanding to the contrary.
There is, however, no reason why the engineer should not retain
copies of such documents as a part of his stock of knowledge and
engineering equipment for other work. The information thus col-
lected and preserved may be of great assistance to him in future
engagements, and it may sometimes become important as a means
of defending his personal character. The privilege of using infor-
mation acquired in the services of a client is subject to one condi-
tion that no honorable engineer will violate. Such records and
facts cannot be used to oppose in any way the business interests of
the client for whom the original work was done."

I would say that this answer deals fairly with the question at
issue, because it secures for the client and also for the engineer the
largest measure of benefit without harm to any one. It is reason-
able and just that the engineer should retain copies of notes for his
own protection in case afterwards the quality of his work should be
called in question. A good example of such a case was furnished
by Mr. Cummings in the meeting of the Montana Society of Civil
Engineers in the month of April, 1894:

"An engineer in that State is often called upon to run some
important connection lines in the mines, and the execution of the
work after it is laid out devolves upon the mine superintendent or
foreman. If he should fail to follow the engineer's lines and in-
structions the work when completed might not connect, and the
engineer would be liable for an action for damages. If he had
parted with his original notes he would have nothing to show that
his work had been correctly done and where the fault really lays."

42 ASSOCIATION OF ENGINEERING SOCIETIES.

I take leave to say here that in the same meeting the opinion of
those present was that the employer was entitled to all the notes
and information obtained from any survey, but that the engineer
making the notes ought to have the right to retain either the original
notes or a copy of the same whenever he considered them of impor-
tance for future use, provided they were not used to the detriment
of his employer's interest.

Let us now leave off the discussion of our question as related
to time work and enter upon the study of cases of the second class,
where the engineer is doing piece work. The characteristic feature
of the relation between the engineer and his client under these cir-
cumstances is that a certain amount of work is to be performed,
the compensation for which is not to be measured by the time
involved nor the necessary labor, but solely by the results obtained.
Generally speaking, the parties enter into a contract by which the
client agrees to pay a certain sum, in consideration of which the
engineer agrees to produce certain results.

Referring to these cases, I would say that from a legal point of
view there can be no other obligation on the part of the engineer
than to comply with the terms of the contract. I do not think that
under the circumstances the client can have a legal right to any-
thing else than what he has contracted for. The understanding is
involved that the engineer is not going to be paid for his time, and
is to have no claim upon the client for compensation until these
results have been delivered. A part performance of the contract
does not entitle him to a proportionate part of the compensation,
and he can recover nothing until all the work is done. Only when
the failure to complete the work or perform the contract in full is
not the fault of the party who has agreed to do it, or if he has been
wrongfully prevented by the other party from completing the work,
is he entitled for what he has done. On the other side, if the
engineer fails to perform his part of the contract he cannot be com-
pelled to perform the contract against his will, but only damages
can be recovered for his refusal unless there be no adequate remedy
at law in money or damages. If, therefore, the contract calls for a
map, a plan or a report, which is to be prepared by the engineer,
the client has no right to anything besides this map, plan or report.
The engineer is not paid for his labor, but for the map, plan or
report, and whatever additional fruits his labor may have had
belong to himself. For this reason I think that the original field
notes belong to the engineer, unless the contract provides otherwise.

It is probably on account of such considerations that many con-
tracts entered into between corporations or parties, who desire to

FIELD NOTES OF A CIVIL ENGINEER. 43

possess the field notes, contain a special provision to that effect.
The contract between the village of Batavia and the engineer who
has charge of the execution of a sewerage plan for that corporation
provides that the field notes shall be turned over to the village
authorities.

I understand that the contract relative to the re-surveying of
property lines between the city of Rochester and the engineer
stipulates that he is to furnish the city with a correct copy of all
field notes.

Another example of which I know is in connection with the
sewerage work of the village of Charlotte. Also there the field
notes were to be the property of the village. I do not know of any
contracts wdiere objections were made to the preparing and keeping
of copies of the notes. In other specifications for engineering work
no special reference is made to the ownership of the notes, but the
plans and maps are required to show practically all the information
that is contained in the field notes. It appears to me that, wherever
this is practicable, this is a very desirable way of getting the benefit
of the notes, because the data in such form are at once indexed and
ready for reference in the most convenient manner.

Having concluded above that the original field notes belong to
the engineer where the engineer is paid for results, I beg leave to
add here that this ruling does not end the matter. The question
only takes another form, and now presents itself as follows : to
what extent should the engineer impart the information of the field
notes to his client? It is, as a matter of course, a difficult one to
answer, except in a general way, as every piece of work has its
special requirements. It would certainly seem advisable wherever
engineering work is given out by the piece that a definite under-
standing be first reached between the parties, so that no room be
left for personal interpretations.

There occur in actual life, however, a number of cases where
the whole question is carelessly left to the discretion of the engineer,
and I am sorry to be obliged to say that there are many instances
on record where the engineer purposely kept to himself the infor-
mation which was necessary to render his work complete, in order
thereby to secure additional employment. Allow me to cite a letter,
which appeared in the number of Engineering Nezvs of April 19,
1894, on this subject:

'T am at present engaged on a piece of work where the lack
of notes is particularly aggravated. The engineers who make the
land surveys in a certain tow^n but a few miles from New York
charge by the lump sum for each piece of work. Recently some

44 ASSOCIATION OF ENGINEERING SOCIETIES.

differences of opinion arose between the authorities and some
property owners regarding a certain street, of which the grading
had just been completed. I was engaged by one of the property
owners to investigate the question, and on applying at the proper
offices was informed that all notes, cross-sections and detail material
were the private property of the engineers and could not be seen.
Nothing was on file but the profile of the center line of the street
in question, and that gave exceedingly meager information. It was
not until legal proceedings were suggested that the engineers con-
sented to allow a copy of the notes to be made.

"The same men are not only the engineers for the town spoken
of, but also for a city of considerable size. As I happen to live
in the town, these things became a matter of considerable interest,
and upon investigation I find that, though the entire town has been
monumented at public expense and mapped, there is nothing on
record showing that there are any monuments, let alone giving
their location or references. Much work has been done of which
there are not even plans, though ample fees have been paid for the
work to cover the most complete records.

"The entire engineering records are in the same shape. The
excuse is now offered that 'it has not been the custom of engineers
to file the notes or other data,' neither does it seem to have been
their custom to file complete plans or maps.

"In this case the sole object sought for seems to be to impress
the authorities more with the appearance of the maps and profiles
than with their value, as the lettering is very well done and quite
conspicuous, and from appearances it would seem that more time
has been spent on the titles than on the rest of the work. While
neat work is always creditable and always to be desired, fancy
lettering at the expense of valuable data is a waste.

"It seems to me that if your paper would continue to agitate
the question, and if reputable engineers would take up the matter
in earnest, much good might be accomplished. Engineers who are
guilty of such practices, it seems to me, should be shunned by their
fellow-members of the profession. I would suggest that some good
could be accomplished by making such practices a cause of expul-
sion from membership in the various engineering societies through-
out the country."

Although I do not wish to take up the war cry of the author of
this letter, I am bound to admit that the principle for which he
stands is correct, and I would consider this paper incomplete if no
reference was made to the undesirable effects which the practice
of reserving notes of land surveys as private, exclusive property

FIELD NOTES OF A CIVIL ENGINEER. 45

of the engineer has had upon the preservation of important property
hnes. The purpose of the offices of the County Clerks, established
for the recording of all information relative to land properties, has
to some extent been defeated by the meaningless descriptions and
plats which are found in the files, and which render the work of
locating some property lines equal to the solving of a Chinese
puzzle.

The engineering profession cannot free itself of all blame in
allowing this state of affairs to exist, because, although it has not
the power to place the surveys of this country on a firmer basis, it
must be admitted that the practices of some surveyors, to keep the
field notes of surveys carefully to themselves and to furnish, maps
and descriptions with the least possible information thereon, has
largely increased the difficulty of relocating important property
lines. I would add that this practice cannot be considered as in the
interest of the engineering profession, and must have the tendency
of lowering its standard among other professions and in the com-
munity at large. I have seen this summer in the hands of attorneys,
representing neighboring property owners, plats prepared by pro-
fessional surveyors showing the location of the dividing line
between these properties thirty feet apart. They are located in the
dock section of this city, and where land is very valuable. Several
months have passed since, and, so far as I know, no location has as
yet been made, so that it will be necessary to compromise. Is it a
wonder that the public has no high estimation of the surveying
business? Such a condition of affairs could not have come about
if each engineer had done his work faithfully and fully, and is
largely due to the practice of furnishing plats and descriptions of
land without the necessary information for re-establishing the
boundary lines. I would say that although the contract may not
require him to turn over the field notes to his client, yet the engineer
is under the obligation to complete his work, and any map or plat
which does not contain sufficient data to enable any surveyor to
relocate the property and to ascertain its location with reference to
abutting properties cannot be said to be complete. This question
has been fully discussed in the editorial of Engineering News of
March 29 of last year, from which I beg leave to copy :

]Mr. Raymond says that the question of what constitutes a sur-
vey arises at once in this discussion, and the answer must depend
upon the object of the survey. Surveys for sv:bdivisions of large
tracts, or surveys intended for establishing the boundaries of a
known tract, or for determining a description when the boundaries
are known, are alone considered here. The principle enunciated
applies, however, to any survey.

46 ASSOCIATION OF ENGINEERING SOCIETIES.

"A survey is the operation of finding the contour, dimensions,
position or other particulars of any part of the earth's surface, and
representing the same on paper. The setting of corners, or monu-
ments, and their description becomes a part of the survey, and the
maps, together with the notes, should show faithfully the ground,
the work done and the items mentioned. The purpose of establish-
ing corners or monuments is to mark on the ground the boundaries
of tracts, to plainly define the location with reference to other tracts
and to enable future surveyors to correctly trace the boundaries.
The survey is evidently not complete until the corners are fixed,
proper information obtained and the same put into the maps and
into the notes.

"The doing of all this constitutes a survey, and the question
now is to whom does this survey belong? Mr. Raymond believes
it belongs to the individual who pays for it, and it is hard to see
how these surveys, or any part of them, can become the sole
property of the surveyor. The latter may keep notes to facilitate
his future work, but he cannot properly claim a single note made
in the time paid for by his employer.

'Tf, however, the surveyor takes the work not on time, but for
a definite sum for the entire job, he may take as much time and as
many private notes as he likes. But, as he is bound in honor to
return to his employers the survey complete in every detail, it is not
obvious that his private notes would be of great assistance to him in
securing further work, especially when it is remembered that pro-
fessional men of repute do not bid against each other for such
work. His reputation for accuracy and honesty will be worth
much more than any quantity of private notes.

"The records of monuments and street lines made by a city
engineer are no more his private property than are the records of
the city clerk, auditor or treasurer. Court decisions indicate the
correctness of the position here taken, though much laxity is shown
in this respect by city engineers and county surveyors. The method
of regulating the pay of these offices has doubtless much to do with
the practice. Where the surveyor receives no salary, but is allowed
to collect certain fees for work performed, there is some color to
the claim that his work is private work and belongs to him. That
this is not true concerning the public work done by these surveyors
and engineers is believed to be evident from what has proceeded."

The editorial article goes on with laying down a set of rules to
which each property map should conform, and further suggests the
enactment of laws to force compliance, but I prefer here to finish
this paper.

FIELD NOTES OF A CIVIL ENGINEER. 47

I have observed with pleasure that gradually many landowners
in the suburbs of this city are placing permanent monuments at
important corners, and if this practice is extended the value of
private field notes will surely lessen.

If I am correctly informed, the practice of considering notes of
surveys, relative to other people's land, as private property has
grown out of the undeveloped conditions of this country in years
gone by, when the engineer's private office was the only depository
of such records. I have no doubt that in the course of time the
importance of public records will be more and more realized, and
with their growth and development will come an end to "private
field notes" as a factor in the engineering profession, in which they
should have no place.

^

48 association of engineering societies.

mecha:nicai. draft.

By Henry B. Prather. )

[Read at the regular monthly meeting of the Engineers' Society of Western
New York, Buffalo, N. Y., July i, 1895.]

Probably no subject is of more importance to-day to the engi-
neer and to the manufacturing and steam using world than that of
the economical combustion of fuel in the furnace of the steam
boiler. That even with the best arrangements of modern steam
plants for the conversion of calorific into mechanical energy but a
small efficiency is obtained is a well-established fact, and yet pos-
sibly more startling than some realize. Theoretically each horse
power should require about 0.212 pounds of coal per hour, and yet
the very best engines and steam plants require from i-| to 2 pounds,
— i.e., about ten times as much and good practice fifteen times as
much and the great majority of good engines in daily use fifteen
to twenty times as much, — i.e., 3^ to 4^ pounds coal per horse power
per hour and show a ratio of actual performance to the full calorific
power of fuel consumed of 5 to 8 per cent. A great portion of this
loss of 9-10 to 19-20 of the work represented by the fuel combustion
is unavoidable, arising as it does from the physical qualities of water
employed as a vehicle for the use of heat. A perfect heat engine
could save but about 16.9 per cent. The best designed engine and
steam plant will in fact yield but about 6 to 8 per cent., and hence
the ratio of practical performance to the perfect plant under usual
conditions is about 35 per cent. ; in other words two-thirds of the
heat work that may be striven for is lost. This loss is in the engine
chiefly, and also partly in the boiler, and hence appears the vital
value of improvements in combustion and boiler efficiency which
will tend to reduce this two-thirds loss of possibly available work.

This subject has commanded the best efforts of our greatest
steam engineers for years — men such as Chas. E. Emer}^, John C,
Hoadley, Wm. R. Roney and others have given the subject exhaus-
tive study and experiment — with gratifying results, it is true, but
that there is still a wide field for improvement will be realized when
it is understood that the relative efficiency above referred to of 6 to
8 per cent, has, with such economy facilitating devices as mechani-
cal draft, water grates, improved furnace and boiler designs,
mechanical stokers, etc., been improved upon only to the extent of
10 to 30 per cent. There are, besides the high-class modern steam
plants of comparatively recent installation, a vast number of plants,
large and small, on land and water, where limitations of first cost

MECHANICAL DRAFT. 49

forbade improved devices, and even many liigh-class 1)oiler plants
which are susceptible of great improvement in efficiency, and offer
a large field for apparatus tending to such and obtainable at a
reasonable or low cost. Examples of such plants are the many
small power plants in our hotels, office buildings and factories, and
on board our many passenger and freight-carrying steamers and
barges. There are many applications and devices on the market
which claim to have the panacea for all the evils a boiler plant is
heir to ; some are really of value, some are purely "quack" devices.
Hence a study of this subject is of great value from a negative as
well as from a positive standpoint. It is hardly less worth while to
know the absolute limitations of economy in coal combustion, to
know what cannot be done, to know the good and bad features of
exploited devices, though quacks promise never so much, as to learn
by what means some of the important loss of heat in existing ar-
rangements may be saved and put to use at a reasonable cost and
without undue trouble. It is the object of this paper, by a descrip-
tion of some of the most important experiments and data made and
obtained in the line of boiler economy promoting devices, and
especially of mechanical draft and a brief discussion of the same,
to possibly present some valuable matter and at least start discus-
sion and thought on the subject in the Society. The limitations of
a single paper of this kind and the time allowed the writer for prep-
aration of same will not permit a full consideration of the subject,
and especially detailed accounts of experimental data and the many
arguments pro and con on the debatable points. The importance
of good draft, natural or artificial, for the supplying of sufficient
oxygen for the rapid and economical combustion of fuel has long
been appreciated by intelligent engineers. The gain both in effi-
ciency and capacity obtained by the rapid and energetic combustion
of the various kinds of coal and the resulting high furnace tempera-
ture is well established. Its importance has, however, been gener-
ally conceded only within a few years. The wonderful stimulus
which the development of electrical industries has given to the
building of compound engines has necessitated higher boiler pres-
sures, and this in turn has greatly increased the use of water tube
boilers. High initial furnace temperature is essential to the best
economy with all types of boilers, and especially with the water
tube type, with their large amount of heat-absorbing surface in
close contact with the products of combustion, as otherwise the"
temperature of the gases will be lowered below the point of igni-
tion and will pass up the chimney only partially consumed. To
obtain this high furnace temperature requires proper draft to deliver

50 ASSOCIATION OF ENGINEERING SOCIETIES.

an alnindant supply of oxygen tt) the furnaee. lliis result is
obtained by two well-known means, — viz, natural draft produeed
by a column of heated gases in a chimney of suitable proportions,
"and "forced draft," obtained by mechanically creating an air pres-
sure under the grates with a blower or fan. A third means, less
known, is mechanical exhaust or induced draft, produced by a
suction fan arranged to draw the waste gases from the furnace and
discharge them into a small stack. These are the various systems
of mechanical draft in general use. Special features for further
increasing the efficiency of the apparatus, such as utilizing otherwise
wasted heat in escaping furnace gases to heat the feed water or the
feed or supply air, are often added. There are numerous other
devices, such as hollow "wind grates," in which the grate bars are
hollow and kept full of air under pressure, but constantly escaping
to feed the furnaces through small holes in the grate bars, and
others. The above-mentioned, however, cover the most successful
arrangements. The principal advantages urged for these various
mechanical draft systems over natural draft are, first, the more
effectual combustion of fuel by reason of the more abundant and
intimate supply of oxygen to the furnace, using any kind of fuel;
second, the obviation of the necessity for high chimneys ; third, the
possibility of use of a cheaper grade of coal at the same time with
a proper combustion of the same, and, fourth, the almost practical
abolition of the smoke nuisance by reason of the more perfect com-
bustion of the fuel and gases.

It has been urged that the use of the more rapid draft causes
early deterioration of the grates in the case of the "cold air" forced
or exhaust draft by the great difference in temperature between the
air supplied to the under side of grate and the incandescent fuel on
the upper side ; in the case of the hot draft, either forced or exhaust,
by the great temperatures obtained under and on the grates causing
burning or melting down of the grates. It can be shown that the
first-named evil is largely exaggerated, and can be rendered slight
by taking the supply of air from the boiler room and from over the
boilers ; as to the second criticism, which has also been exaggerated,
the use of water grates, — i.e., hollow grates, — with a circulation of
water in them o^'ercomes the burning out of the grate bars, even
with the maximum obtainable temperatures. There is no doubt
but that many of the old-time "forced draft" applications where
high speed blowers deliver cold air at 2 to 3 ounces pressure under
the grates, and having no economizing device for utilizing the
waste gases escaping up the chimney, are not as efficient as they
should be ; are great consumers of power for fan propulsion and

MECHANICAL DRAFT. 51

destructive of boiler grates and shells. True, the}' do "make steam"
quick, and when coal is shoveled in fast enough they are great
"steam raisers." Of such plants a large majority have-been applied
on ocean steamers where limited space forbids the use of large
slow-running fans and low velocity air conduits, and the principal
object is fast steam-making more than economy of fuel. The value,
however, of the use of even cold forced draft at pressures of ^ to
i| ounces, and still more of the forced or exhaust draft with hot
draft and economizer attachments in effecting an economy of from
8 to 20 per cent., is well established, and from 8 to 36 per cent, is
claimed. Slow speed fans should be used whenever possible, in
order to reduce the power required for fan propulsion. In this
connection a brief consideration of results obtained 1)y eminent
engineers will be pertinent. From the summer of 1881 to May,
1882, at the expense of a number of the largest mill owners in New
England, extended tests of "Marland's warm blast" apparatus were
made under direction of the late John C. Hoadley, M. E., of Bos-
ton, at the chemical works of the Pacific Mills, at Lawrence, Mass.
This apparatus consisted briefly of a "Root" positive blower ex-
hausting the furnace gases upon leaving the furnace through a
number of thin tubes about 3 inches in diameter, over which tubes
the air supply for the boiler furnace was led and warmed, and thus
efifecting the economies of increased air supply, more eiTectual and
complete combustion and warm feed air and its attendant results.
These experiments were on a very practicable and elaborate scale,
every detail being attended to and in degree of accuracy of calori-
metric, anemometric and thermometric work were doubtless
the most extended and valuable tests ever made of the kind. The
most vital point in boiler testing, the analysis of the flue gases, was
very carefully determined and elaborated, and the greatest care
was taken in determining the exact power used in driving the
blower or fan. The results obtained showed beyond a doubt a net
saving of 10 to 18 per cent, over the best obtainable practice with
natural chimney draft, and with air supply at the usual external air
temperatures, at least five times as much as can be saved by any
and all other methods save analogous devices (see Transactions of
American Society of Mechanical Engineers, Vol. VI, pages 676-
842) . This apparatus has been in use several years, and no unusual
deterioration of boiler, boiler grates or the warm blast apparatus
itself has occurred, thus effectively demonstrating its practical
efficiency. The induced or exhaust draft with feed water heating
economizer as applied in many large plants consists of large slow
speed fans exhausting the furnace gases over coils of feed water

52 ASSOCIATION OF ENGINEERING SOCIETIES.

heating pipe and discharging the refuse gases up short stacks or
chimneys and outdoors, thus utiHzing the waste, heat of the gases to
heat the feed water for the boilers. Mr. Wm. R. Roney, M. E., of
Boston, Mass., is probal)ly the best authority on this form of
mechanical draft. The results of his experiments in brief, as lately
stated by him, are the first cost of a properly designed mechanical
exhaust draft plant is very much less than that of a suitable chim-
ney of equal capacity, usually averaging 75 to 80 per cent, less ; and
as to power required for fan propulsion in a plant with 6000 H. P.
water tube boilers, the power required to drive one fan to do this
work was 6-10 of i per cent, of the l)oilcr horse power developed
or estimated in coal per horse power per hour at $3.00 per ton ; the
fuel cost of running the plant one year was 2 per cent, of the esti-
mated cost of a natural draft chimney for the plant. In other
words, it would not pay to build a chimney so long as money was
worth more than 2 per cent, per annum. In another case the power
required was less than 10 H. P. for each 2000 H. P. produced, or
less than half of i per cent, of the power developed by the boilers ;
and in a tabulation of the results obtained in nine large plants the
average net fuel saving was about 15.2 per cent., and in some nearly
20 per cent. ; and, in addition, there was the economy in first cost
and in the money which would otherwise have been invested in
chimneys.

Referring to those feed water heaters conmionly known as fuel
economizers, they are certainly no new thing, having been manu-
factured in England for over fifty years and in this country for
three or four years, and have been imported for many years. They
have been used, however, almost exclusively in chimneys with
natural draft, and hence on account of the reducing effect on the
draft caused by lowering the temperature of the gases and retard-
ing their flow it is always necessary to provide a better draft where
they are to be used than when not ; hence, higher and larger chim-
neys. Good practice requires that chimneys with economizer should
never be less than 200 feet in height. Certainly, the failure which
has sometimes attended the introduction of the fuel economizer has
often been due to placing them where the chimney draft was none
too good before ; hence, they not onl\- failed to show an expected
economy, but also impeded what draft there was. Of course these
objections do not hold when mechanical draft is used; a short
chimney can be used only high enough to permit the discharged
gases to clear neighboring buildings, and the heating surface in the
economizer can be made a maximum and the gases cooled to a
point which would destroy the draft altogether in even the tallest

MECHANICAL DRAFT. 53

chimney using natural draft. In the designs of new plants aiid
chimneys for same this point of small chimney required is extremely
important in first cost, especially in this day of valuable land around
our city power buildings. .Mechanical draft possesses great advan-
tages over natural draft, especially in its flexibility of application
and adaptation to both large and small capacities and in its ability
to meet sudden and excessive demands for steam either by an extra
turn of the throttle valve or by use of an automatic regulator con-
trolling the steam supply to the fan engine, and hence adjusting
the speed of the fan according to the boiler pressure. No such
flexibility of adjustabihty can be had with natural draft. It should
be noted that in no system of exhaust draft so far referred to in
this paper does the suction fan handle the furnace gases at their
furnace temperatures ; they pass through the fan after the major
portion of their heat is absorbed by the economizer or by the
"abstractor," or air supply heating device, the average temperature
of the gase» actually handled by the fan, even with the exhaust
draft, being about 300 degrees, a temperature in no way deleterious
to a fan of proper construction with "a water cap" bearing. The
Howden "hot draft" apparatus has been applied quite successfully
on the lake and ocean boats ; this consists of a blower fan forcing-
cold air at about i^ ounces pressure over tubes (through which are
passing the hot gases from the boiler furnaces), and thus a1)sorbing
most of the heat from the furnace gases, thence discharging this
hot feed air at about ^ to -J ounce over and under the grates. Tests
of these plants on the lake steamers "Madagascar," "Nicaragua,"
"Harvey H. Brown" and others have, on a comparison of compara-
tive fuel consumption per ton cargo carried per mile, showed a gain
in efficiency of 28 per cent, over work done without the hot draft
and using a poor grade of bituminous coal ; and showed an average
combustion of 1.65 pounds fuel to each indicated horse power
developed per hour, a most remarkaljle showing for the mechanical
hot draft, as well as for the complete steam plants. The Ellis and
Eave's system, as applied to the power plant for the American Line
of steamers in New York city is on the same principle as the Roney
exhaust draft plants, excepting that, instead of the feed water heal-
ing economizer, a feed air heater is used and hot air supplied to
boiler; and for this system a gain of 20 to 25 per cent, is claimed,
and certainly 15 to 20 per cent, can be relied upon.

Before closing this review of the most important svstems
before the public to-day the "Keene Fuel Economizer and Smoke
Consumer," a form of mechanical draft, demands attention. This
device consists of a fan blower taking in ordinary air on one side

54 ASSOCIATION OF ENGINEERING SOCIETIES.

and connected by means of a suitable pipe witb a cbimney flue near
the breeching of the boiler on the other side, so as to take in more
or less of the flue gases to heat the air, and delivering the mixture
of air and gases to the ash pit of the furnace, whence they are forced
through the grates and the fuel bed. Dampers are placed on each
side to regulate the proportion of air and flue gases admitted to
the blower. Tests of this apparatus under direction of the smoke
commission of the city of St. Louis, Mo., showed an average tem-
perature of the air discharged under the grates of 235° and a gain
in efficiency over the same boilers without the device of 38 per cent. ;
and when using the fan, but not heating the air supply, a gain in
efficiency of 26 per cent, and a smoke record of reduction of smoke
emitted from stack of 90 per cent, is claimed. It will be noted
from the above matter that the simple "forced draft" application of
mechanical draft, consisting of a blower discharging ordinary air
under the grates of the boiler, has not, so far, been largely touched
upon. But there are twenty of these applications, however, to one
of the more elaborate economizer or hot draft arrangements, and
the proportion is probably much larger. There is no doubt what-
ever but that the addition of the special features referred to for
further increasing the economy of the mechanical draft plant do so
enhance their value, but there are, as before stated in this paper, a
vast number of boiler plants already installed, and mostly of small
size, whose efficiency is susceptible of increase and oftentimes badly
in need of such an increase by the addition of the simple forced
draft, and where the cost renders the same the only available
apparatus. Great corporations, with their hundreds of thousands
involved, can afford the most complete equipment and profit by the
same, but the smaller steam users must often, and very often, pur-
chase the lowest in price that they can get, and still improve their
poor draft or abate their smoke nuisance, or both. A description
of a few representative plants of this kind will be of interest. The
elements are about the same in all cases, excepting in very small
outfits of 30 horse power or under.

A steel plate fan with direct connected, single or double engine,
usually vertical, exhausting the air from the hottest part of the
l)()iler and engine room (thus serving to help cool the room, as
well as assisting the boilers), discharges this air under the grates
in case of stationary land boilers, or into wind boxes in front of
ash doors for marine boilers, with suitable dampers and levers
readily accessible for operation of same. An automatic steam
regulating valve on the steam supply pipe to the engine for the
automatic regulation of the engine speed in proportion to the pres-

MECHANICAL DRAFT. 55

sure tlesired to 1)C carried on tlic boilers is generally pr(jvi(le(l. The
velocity of the air at the fan outlet is carried at from 'l to i^ ounces
pressure, and under grates from ^\ to j ounce ; and a delivery for
tubular boilers of about 150 cubic feet of air per square foot of
grate surface per minute, and for water tube boilers from 200 to
300 cubic feet per square foot grate per minute is effected. A plant
like this, with a 70-inch (narrow fan) and five by seven single
engine was placed in the power and light room of the large dry
goods store of Barnes, Hengerer & Co., of this city, about two years
ago by the Buft'alo Forge Company ; has run successfully ever since
with no unusual repairs, and has shown a net saving of at least
30 per cent, in the fuel bills and a relative gain in efficiency of 10
to 15 per cent., with a practical abolition of the smoke nuisance.
The remarkable economy in the fuel bills arises in this case from
the fact that before the introduction of this system the best pea coal
and anthracite was burned, while with the use of the forced draft
apparatus a soft coal slack is used, with tne addition of one barrel
of good hard coal to about six or eight of the slack or cheap coal.
Plants have been installed in the Genesee and Broezel Hotels, about
twenty factories and manufacturing establishments and on the lake
steamers "Wm. H. Gratwick," "Caledonia," "Italia," "Bulgaria,"
"Australasia" and others, with practically the same results, by the
same firm. The illustrations herewith show the method of applica-
tion.

As a conclusion it is pertinent to emphasize the fact that the
most perfect mechanical draft plant will be a failure nine times out
of ten if the firing of the boilers is not properly attended to, and the
too rapid rushing of the air through the grates or the improper
impeding of the draft by the kind of firing and the manner of
stratifying the coal on the grates is not prevented. Engineers may
design, and inventors may scheme, but the king of the boiler room
is the fireman. Mechanical draft is a help to the fireman as well
as to the man who pays the coal bills, if he would but appreciate it.
The day of the tall chimney, belching forth its clouds of black
smoke, which many a time has been cited as glorious evidence of
prosperity, is about over, and the day of the development of one
mdicated horse power by one pound of coal, with all its enormous
economies to the steam-using world, approaches, and no single
agency in this good work deserves more praise or has been more
useful than mechanical draft.

DISCUSSION.

Mr. Rodgers.- — The speaker struck the keynote when he said
the success of any method depended upon the fireman. I, how-

56

ASSOCIATION OF ENGINEERING SOCIETIES.

ever, take exception, and desire an opportunity to discuss it at an-
other time.

Mr. Hollovvay. — What is wanted is perfect combustion, no
matter how it is obtained. Even the best apphances are dependent
upon careful handhng.

ADDENDA.

Hoivden Hot Draft.
Report of chief engineer of Goodrich Transportation Com-
pany, of Chicago, showing resuUs of fitting three of their steamers
with this form of mechanical draft. During season of 1893 the
steamers used Pittsburg coal without the Howden draft, and during
season of 1894 they used Indiana coal (which could not be burned
before) and with the Howden draft:

Miles
Str. Indiana, run.
Season,

Tons of
coal used.

Cost.

Pounds of

coal per

mile.

1893 24,870

1894 24,500

2,795
2,633

19,191.90
5.641.57

224.7
214.9

Str. Racine.
Season,

1893 23,660

1894 22,770

2,350
2,000

8,759.71
3,987.50

198.7
175.7

Str. Atlanta.
Season,

1893 23,615

1894 22 6S0

2,791
2,320

8,903.40
4,838.44

238.
205.

5 Pt". ct.

Cost per
mile run.

•37
•23

Saving.

38 pr. ct.

•38
12 pr. ct. .18 50 pr. ct.

15 pr. ct.

.38
.22

40 pr. ct.

iMcchiDiical Exhaust Draft zvith Feed Water Heating Economizer.

Report of Wm. R. Roney, M. E., of Boston, Mass., on test
made.

The per cent, saving is only a comparison, using same kind of
coal. Undoubtedly a comparison of fuel cost between necessary
kind of fuel to use without and possible kind to use with the exhaust
draft would show a saving of 30 to 50 per cent.

Test of economizer and mechanical draft plants, showing
initial and final temperature of flue gases and feed water in degrees
Fahrenheit.

Plants
tested.

Gases

Gases

Water

Water

Gain in

Fuel

entering

leaving

entering

leaving

temp, of

saving

economizer.

economizer.

economizer.

economizer.

water.

per cent.

I

610

340

no

2S7

167

16.7

2

505

212

84

276

192

19.2

3

550

205

185

305

120

12.0

4

522

320

155

300

145

14-5

.S

505

320

190

300

no

II. 0

6

465

250

i«o

295

115

■ 11-5

7

490

290

175

280

105

10.5

8

• 495

190

155

320

i'5

16.5

9

541

255

130

311

181

18.1

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

As

SOCIATION

OF

Engineering Societies.

Organized 1881.

Vol. XXIII. AUGUST, 1899. No. 2.

This Association is not responsible for the subject-matter contributed by any Society or
for the statements or opinions of members of the Societies.

FOREST MANAGEMENT IN MAINE.

By Austin Cary, A. M., Forester to the Berlin Mills Co.

[Read before the Boston Society of Civil Engineers, May 10, 1899.*]
In any broad view of the forest interests of Maine we should
begin with topography. The ruhng topographical feature of the
State is a broad plateauy stretching from west to east, dividing its
area into a northern and a southern slope. Of these slopes the
northern is the smaller, embracing the watershed of the St. John
River. The southern slope is a belt along our entire coast line on
the average 140 miles wide.

A further feature to be noticed is the fall of the divide from
west to east, from the foot of the White Mountains, in New Hamp-
shire, to Mars Hill, on the borders of New Brunswick. The Range-
ley Lake system at the west is between 1400 and 1500 feet above
sea. Moosehead Lake, at about the center of the line, lies at 1020
feet. The highest point on the boundary between Maine and New
Brunswick is about 500 feet above sea level.

The botanical features of the State hang largely on the topog-
raphy. In the southwest, for instance, a large district, low-lying
and with a mellow soil, is united botanically with Massachusetts
and Southern New Hampshire. Oaks are prominent in the woods
here, and white pine was the staple of the original soft wood timber.
On the other hand, the plateau country presents a Canadian flora.
The hard wood trees are the birches, maples, etc., characteristic of

*Manuscript received July 11, 1899. — Secretary, Ass'n of Eng. Socs.

fFor the original statement of these relations, and valuable informa-
tion as to Maine's natural features and resources, see Wells' "Water Power
of Maine."
5

58 ASSOCIATION OF ENGINEERING SOCIETIES.

a colder region, and spruce forms the largest and^most valuable part
of its soft wood timber. In the west, where the boundary of the
plateau is sharp, and where it has its greatest elevation, the con-
trasts in timber stand are greatest. Eastward, with the easier
topography, there is more variety and mixture.

We must next observe that a large part of the State of Maine
is destined to remain permanently wooded. The bulk of our popu-
lation is now and will continue to be located in the lower southern
part, where milder climate, abundant water power and areas of
fertile soil offer advantages. Again, there is a strip of land with
easy topography and very fertile soil along the New Brunswick line
in Aroostook County. Out of these areas indeed a large propor-
tion is wooded, and some bodies of land included within them are
of such a character that they never will be inhabited or cultivated.
For the great district remaining, about half the area of the State,
the same thing is true. It is high in the first place, and the season
of growth is short. As a rule the topography is rough and the soil
poor. Considerable of it, indeed, is little more than ledges and piled
up rocks.

Half the area of the State, then, about 15,000 square miles,
seems destined to be permanently forest. This is an area twelve
times as large as the Black Forest* in Germany. The States of
Massachusetts, Rhode Island and Connecticut, taken together, just
about equal it in area. The importance of this body of land as a
source of wood material is evident from the statement. The rela-
tion to it of business- development will be seen later on.

Since its settlement Maine has always had a lumber business ;
that is to say, lumber has been cut and sawed here not only for local
consumption, but to export to other communities. Many of the
earliest settlements in the State were built about accessible mill
privileges, and later movements of population have in considerable
measure been related to woods and mills.

The development of the lumber business has proceeded accord-
ing to evident laws. In the natural condition pine was at once the
largest, most valuable and most accessible timber that the State
possessed ; pine, therefore, was the first timber to be taken. It was
taken, too, where most easily accessible, along the coast and on the
banks of the rivers, where it could be floated to mills, run by tide
or located at the first powers above their mouths. As the best class
of timber failed in the first locations men pursued it further up the
streams, or spread along the coast to other regions which had not
yet been drawn upon. For a long period, however, they cut
*The amount of actual forest land is here meant, not the gross area.

FOREST MANAGEMENT IN MAINE. 59

only pine, even after they had to go long distances for it.
In fact, the State had been settled nearly two hundred years, and
the larger rivers had been culled for pine clear to their sources on
the plateau, before there was a profitable market for other soft
wood timber. At length, however, the limits of the pine supply,
a supplv never so al^undant per unit of area in the northern wilds as
in the low-lying parts of the State, began to be approached, and
spruce began to take the place of pine as the staple of luml)er Lxpurt.

Since about 1840. then, the bulk of the luml)er exported from
JMaine has been spruce, which was cut in the great forests of the
plateau and sawed at mills located low down on the Penobscot,
Kennebec and Androscoggin Rivers. Since the early 70's, how-
ever, the saw mills have had a competitor in the log markets of the
State in the shape of mills manufacturing wood paper. Beginning
about 1870 in a small way, pulp and paper manufacture rapidly
increased, and in ten years had become well established. After a
period of experimentation spruce wood was settled upon as by far
the best technically for most uses, and it is now exclusively used in
most mills. The amount of this use can be judged of from the mill
capacity. In 1894 the pulp and paper mills of Maine numbered
forty, and represented, as reported to the State Labor Commis-
sioner, an invested capital of $12,000,000. They employed between
4000 and 5000 men, and had a daily capacity of 397 tons of paper
and 765 tons of pulp. At the beginning of 1899 the mills of Maine
reported to the directory of the trade a daily capacity ( not produc-
tion) of 650 tons of paper and more than 1000 tons of pulp. In
this respect Maine stands second only to New York among the
States of the Union.

Here we get at what is at once the big and the pressing matter
in connection with the forests of Maine. Paper making is one of
the great, stable and growing industries of the country. It is
mainly dependent on spruce wood because spruce excels in length
and strength of fiber, and is most readily reduced to the macerated
condition. Xow the woods of Maine possess the largest stock of
spruce wood existing within the limits of the United States, while
probably in a still greater degree they embody growing capacity.
The question what that resource amounts to, the question, too, how
it is being used and what may be done to foster it, are questions of
concern to the whole country.

The people of Maine have been behind in the appreciation of
their natural resources. The State is approximatelv 31,500 square
miles in area. Wells in 1869 estimated, excluding water and culti-
vated land, that two-thirds of it, or 21,000 square miles, was covered

6o ASSOCIATION OF ENGINEERING SOCIETIES.

with woods, and the conditions since then have not greatly changed.
The area destined to be permanent forest, as earher defined, we
may set at about half the area of the State, or 15,000 square miles.
Probably more than that, even taking out waste areas in the shape
of burnt land and barrens, now possesses spruce of at least some
small value. As to amounts of timber standing, no careful sum-
maries have ever been made, except for some comparatively small
portions. Much of the country never has had the timber upon it
estimated, and if that had been done a vast amount of digestion
and re-exploration would be required before the figures could be
safely compared and summarized. The best that can be done here
to give an idea of the condition of the Maine woods is to describe
very generally and cursorily different tracts of country.

Some 12,000 square miles on the St. John and upper Penobscot
are timber land of very varying quality, containing every variety of
stand natural to the region. Considerable areas in the aggregate
have never been cut for spruce, and the cutting that has been done
has generally been for saw^ logs of good quality merely, and pretty
loose and unsystematic. The area named has not been seriously
damaged by fire. Here, due to its area rather than quality, is the
great supply of spruce wood now existing in the State.

The Kennebec River drains 5800 square miles, but less than
half this area could be classed now as actually spruce producing.
But at the heads of the streams, in very difficult situations, small
tracts yet remain that never have been cut for spruce ; but the
remainder has been cut through, much of it severely and several
times over, while both in early and more recent years the region
has suffered severely from fire.

The Androscoggin River possesses about the Rangeley Lakes
the best spruce timber land in the State. It has been saved from
fires, and, due to the roughness of the land, much of it has thus far
escaped cutting. The drainage is of small area, however, 2750
square miles in Maine, and half of that, in the lowlands of South-
western Maine, cannot be considered as spruce producing. There
is also a great mill capacity located in this region. At Berlin, _
Livermore and Rumford are some of the largest paper mills in the
world, and while they draw in a considerable portion of their wood
supply from Canada and elsewhere by rail, the Androscoggin drain-
age itself is being called upon for timber at a rate and in a manner
that will within a few decades, if continued, blot it out as a source
of spruce timber.

Other items of the timber supply of Maine are of minor impor-
tance, at least in the present connection. Southwestern Maine has

FOREST MAXAGEMENT IX ^^lAINE. 6i

white pine as its main soft wood growth. This is a quick-growing
wood, and on it that part of Maine does a considerahle lumber busi-
ness. This item is seldom thought of in connection with the lumber
supply of the State, but, as a matter of fact, wooded lands in this
region are probably producing more per acre than the backwoods.
Pine, however, is seldom used in the manufacture of paper.

Most of Washington and Hancock Counties, in the southeast,
consist of poor and rocky land, fit for nothing else but the growth
of timber. This country, however, has been long and hard cut.
A good half of its area, too, has been burned over, and while burned
land almost always quickly grows up again, fire changes the char-
acter of the growth and sets it back as a producer of lumber. As
to spruce supply, as available now and in the next fifty years, the
main items have been considered already.

Under the circumstances it is perhaps rash to set any figures
for the timber resources of Maine. In stating clearly, however,
that such a figure can be merely a rough guess consequences of pre-
sumption are deprecated. It seems probable, then, that twenty-five
billion feet, board measure, may approximate the amount of spruce
wood standing in the State. The total lumber cut in the State in
1896 was something over six hundred millions. Of this probably
five hundred millions was spruce. About two-fifths of this went
to the paper and pulp mills.

Six hundred millions is equivalent to 30 feet per acre on the
gross area of tlie State. Five hundred millions may be 50 feet
per acre on the area of what we might call spruce producing land.
These figures are within the amounts which such studies as have
been made attach to ordinary cut-over land as its yearly growth.
Certainly, they are small in comparison with what we know scien-
tific forestry has produced elsewhere.

The general inference to be drawn from these facts is not a
discouraging one. Our resources are still great, and we may feel
justified in using them freely. It is to be remarked, however, that
paper mill capacity in the State is being rapidly increased at the
present time, and promises to reach in the near future a much
greater development.

It might be remarked of the foregoing that it is Intsiness and
not forestry. The reply to that is that whatever forestry we are
to get in Maine, at least in the near future, must be worked out
■under business conditions. The State of Maine is not likely to
interfere by law with the conduct of private business. Neither does
it appear that State ownership of wild lands to any great extent is

62 ASSOCIATION OF ENGINEERING SOCIETIES.

iikeh' to be brought about. Maine is poor in comparison with the
States that have inaugurated that policy, while it is not called to
that course by such urgency. Agriculture has not, to our knowl-
edge, been affected by the cutting of our forests. The flow of our
rivers has not been affected to such an extent as to elicit protest or
a call for investigation. The climate of Maine is such that almost
all denuded or burned areas very quickly reclothe themselves with
growth which, if not valuable at once for timber, at least protects
the surface of the ground beneath it.

Topographical model of township No. 3 R. 5, Franklin Co., Maine, showing, in addition to
the waters and relief, bogs, roads, trails, section lines, etc.

The man therefore who would throw in his lot with the forests,
who would economize in their use and maintain their growing
power, must bring himself to bear on the forces in the field. He
should not be choice in his weapons. The spread of information
will accomplish much, but competition, when it can be brought to
bear, may prove a more effective tool. Forestry should 'seek to

FOREST MANAGEMENT IN MAINE. . 63

ally itself with business, to promote the success of careful and fore-
sighted concerns. The forester, if he would work directly on the
problem of management, must work in private employ and in ac-
cordance with its fundamental conditions. First among these is
the necessity of making profit. Should the forestry practiced lead
to loss, the business goes down and the forester's position and
opportunity go with it.

The lay of the land in this quarter will become more evident
if we briefly review the systems of landholding and management
existing within the State. First is the stumpage-selling system,
long current and now in vogue in the timber lands of central and
northern Maine. The land title in this case is held by men wdio
neither own mills nor cut logs. Neither, as a rule, are they practi-
cal woodsmen. They are simply men of means who have acquired
lands by inheritance, or who, having found out that timber land is
a safe and profitable investment, have bought it on the judgment of
others. They sell lumber standing at so much a thousand, and do
not as a rule exercise, either directly or through their representa-
tives, any efifective supervision as to how it is cut. The man who
buys the stumpage may or may not own mills. At any rate, he is
interested in getting as good a lot of logs as possible for the stump-
age paid and with the least outlay of time and money. He cuts
accessible bunches therefore, and leaves distant or scattering timber.
He cuts his stumps as high as is convenient, and throws away a
quarter of his lumber in the shape of the knotty tops, which, though
capable of use, are of distinctly less value. He slashes through the
country anywhere with his roads, and makes no attempt to spare
young growth or to save such as is killed if it comes below the class
of most desirable timber. In examining these matters a few years
ago for the United States Forestry Division I found concerns where
only 60 per cent, of the whole volume of trunk wood was saved
from the largest and finest trees, and where, taking into considera-
tion the small trees killed and left, the lumbermen put into the
w^ater less than half of the timber killed.

Such methods as these are an heirloom from former times, but
they are rendered possible in the present only by the system of land-
holding under consideration. The trouble is the interests of the
man wdio does the work are divorced from those of the land on
which he is operating, and that this is not offset by strict contract
and supervision. The power of remedy lies with the landowners,
who are strong parties and who would benefit by careful handling
of their lands. In a few cases this has been done. Thus the only
really conservative force on the Androscoggin to-day is a large

64 ASSOCIATION OF ENGINEERING SOCIETIES.

body of land held in this way which is operated carefully and with
a view to the future. As a rule, however, nothing can be expected
from present owners. The only remedy is to buy them out.

Again, landownership in the past has often been a subsidiary
part of the sawmill business. Men engaged in lumber manufacture
found they could buy land cheaper than logs, and did so, going on
often to do their own lumbering. In their cases logging work is
frequently somewhat more economical, but it can hardly be said to
be more foresighted. The man's object here is to stock his mill.
Beyond that the land has no value.

An example here, an extreme one, to be sure, will serve to show
what is sometimes lost under the present methods of conduct of the
lumber business. I happen to know where a very large amount of
spruce timber, belonging to one concern and standing in one com-
pact body, was killed by the ravages of insects. Within two years
from the death of the trees there must have been a loss on the
lumber not far from 50 per cent. After five years or so there would
be nothing there worth going after. And yet, due to stupidity,
obstinacy or to financial pressure, no adequate measures were taken
to save it. In fact, the dead timber was left to rot, while nicely
growing land that had once been cut through was stripped off
beside it because logs could be got there a little cheaper. What
good forest management consists of in such a case is very evident.
The fact illustrates the principle that good forestry is very often
identical with sound business. Neither one is possible if there is
too great financial pressure.

Whatever the economy of his work, from the point of view of
forestry, there is one fundamental trouble with the sawmill man's
attitude to his land. He regards it simply as a source of stock for
his mill. He buys the land to strip it. He wants to get his money
out quickly and put it into some other investment. So he takes
principal as well as interest, the stock of wood needed for growth
and reproduction, and not merely the mature crop. If, in years
back, owing to slack methods and the condition of the market,
a good deal of growing lumber has been left standing, that is
entirely aside from his main purpose and intention. At present
some of our most destructive and thoroughgoing cutting is being
done by sawmill men.

Since the pulp and paper mills began to be a strong factor in
the log market of the State a good deal of hue and cry has been
raised, because they cut or caused to be cut much of the small
growing lumber. Small logs could be used by them to quite as
good advantage as large ones, while, since they were less desirable

FOREST MANAGEMENT IN MAINE.

65

to the sawmills, they could be had much cheaper. There have
been, therefore, of late years two classes of logs on our larger rivers,
saw logs and pulp, selling at considerably different figures.

The pulp mills have been justly criticised on this head, and yet
there are considerations here that should weigh strongly in their
favor. They have worked great economy in the use of our forest
resources, have taken vastly more from our lands than would have

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Height curves, showing comparative growth of spruce and pine and of spruce under dif-
ferent conditions.

1. Cur\e of spruce grown on good soil, — land cleared by fire.

2. Curve of spruce on very poor soil, — same tract of burnt land.

3 and 4. Curves of spruces grown up in mixed hard and soft wood under shade.
5. Curve of a pine on same site as No. i.

been possible under the old regime. The pulp mill can use the
knotty tops ; a seamy or crooked tree is as good as a perfect one ;
the small trees cut or smashed down, which in other times were left
to rot, can all be utilized by the pulp mill. Sometimes tracts of
land are given a value, and can be operated at a profit for pulp,
which would never have been cut for saw timber.

And if, in the direction of economy, the paper mill has vastly
raised the standard, it has seemed to promise the same in the direc-

66 ASSOCIATION OF ENGINEERING SOCIETIES.

tion of foresight. In beating about among the hmiber consumers
of the State, as just mentioned, tlie fact forced itself upon my notice
that the men who were thinking pointedly about the matter of timber
supply, the men who were most interested in anything that promised
to increase and extend the yield from our forests, were the owners
of pulp and paper mills. And, on consideration, the reason for this
is plain. It is their great investment in mill plant, an investment
dependent on forest supplies for life and profit. The contrast with
the sawmill business is striking, and, in the present connection,
vital. A plant that will convert seven millions of spruce wood a
year through the stages of ground wood and chemical fiber into
finished paper requires a capital, mostly in the fixed form, of not
far from a million dollars. Many of our operating sawmills, on
the other hand, represent a valuation of only $10,000 to $20,000.
The paper mill man is tied ; he is in the business for a long period.
The sawmill, when lumber gets scarce or business poor, may be
abandoned.

Thus we have had a movement among the paper mills, yet in
its infancy, but apparently increasing, to back themselves with land
enough to render them independent. With that movement has
gone the purpose to treat those lands carefully and with foresight.

In this movement it seemed as if the financial basis might have
been attained for conservative forest management, as if we had
solved the problem of so disposing of the ownership of our forests
that their value might be preserved and the community at large
derive most benefit from them. Still more was that hope nourished
last year when, at the organization of the International Paper Com-
pany, with control of 80 per cent, of the output of news paper of
the country, a professional forester was employed, and the inten-
tion expressed of living, so far as forest supplies were concerned,
within the limits of actual growth. It looked as if the paper mill,
backed by forest land, the two operated together as one great per-
manent investment, was the form in which the bulk of our Maine
woods might in time be held. This appeared the more likely be-
cause, as many of the mills have been situated, land sufficient to so
stock and fortify them could be had for a less investment than the
cost of the mills, so that heavy profit from the land part would be a
minor matter in comparison with the safety and prosperity of the
whole.

We may hope for much from this idea, and yet must be cautious
in banking too heavily upon it. It seems sometimes as if American
business enterprise were too grasping, reckless and shortsighted
to have safely intrusted to it a great natural resource. Heedless
desire for immediate gain tends to the overstocking of every profit-

FOREST ^lANAGEMENT IN MAINE. (ij

able line, and ruinous prices and cutthroat competition follow in
its wake. Thus men reckoning at the very closest on the price of
paper are compelled to figure on the price of pulp wood as one
element,- and if that is done too closely it shuts out the opportunity
to do anything for the land. On the other hand, the danger in
combination is that business will be conducted with reference to the
stock market rather than to sound business success. Either exces-
sive competition or wrongly used combination is destructive of
sound, liberal business. Either, in this case, will prevent doing
anything to the advantage of the land.

At any rate, as a safe and satisfactory arrangement for the
holding and operation of forest land, we have suggested to us the
organization of companies of general investors. Forests, carefully
handled, form a very secure form of investment, able to pay a
moderate return without loss of capital. In Europe forests have
proved the safest and surest investment, being used in that way not
only by the noble families and others of the best class of investors,
but being held for revenue by cities, towns and states. On the
other hand, conditions are right here to keep the forest constantly
producing. The investor looks only for interest, and wants his
capital kept intact. By that means sufficient wood stock for growth
and reproduction is left on the land.

There is vastly more in the woods business and in lumbering
than might be imagined by the uninitiated. In developing a town-
ship of land for the first time the first thing to do is to get a road
to it. Along that road, as business is now carried on in the most
progressive localities, is strung a telephone wire. Supplies and
communication are thus assured.

Next comes usually improvement of the streams. Our smaller
streams are generally rough and crooked. Rocks have to be blasted
out of the channel, abutments built to run the logs round sharp turns
and keep them out of the swamps. Dams are constructed to con-
trol and prolong the flow of water. These improvements are costly.
Some of them have a short life. They sometimes compel a concern
to log heavily on a tract while they are there.

This is but a small part of the expenditure, however. On
large lakes logs are towed more cheaply by steamer than by hand.
Three steamboats of different sizes and patterns are employed to
get past the lakes of the Rangeley system, and booms, dams and
piers are needed at various points below. Again, several hundred
horses are used in the woods work of the company by which I am
employed, so that even in the small matter of harness no small

68 ASSOCIATION OF ENGINEERING SOCIETIES.

amount of care is required to keep a supply in stock, to keep run
of it in movement and to keep it in repair.

An Androscoggin logging camp contains as a rule forty or
fifty men. A woodworker and blacksmith are in every crew to sup-
ply it with tools and sleds. Two men manage the cooking, and
often another has special charge of the stable and horses. The
rest of the crew are divided up by the boss into squads ; a teamster
with a pair of horses and sled as the nucleus of each, and with him,
to do the cutting, a crew of usually four men.

This crew, under present arrangements, works largely by itself.
The boss of the whole crew gives it ground to work on, and spots
out its main road. He tells the men in general terms what to cut,
and visits them once a day to see that they are doing as they were
told. Further than that, however, the men run their own work. A
man of experience leads off, spotting his road and having a man to
help him fell the trees. These two men also cut the log off at the
top, cut the limbs off and roll or swing it to where it can be hitched
onto by the team. The third man has to trim the knots close, bark
the log if necessary, so that it shall drag easy, and, when the
teamster comes along, help bind the load onto the sled. The fourth
man, meanwhile, is ahead of all his mates, making a road by cut-
ting out the trees and windfalls, filling up the holes, bridging
brooks, etc. In our woods the men are mainly French Canadians
and immigrants from the British provinces, with some Yankees and
a sprinkling of men from the northern countries of Europe. They
vary much in experience and capacity. Good men, over and above
board, are paid from $20 to $26 a month.

These are the men that the forester has to work with. This
is the organization he will have either to utilize or modify in carry-
ing out the purposes he entertains toward the forest. So far this
organization has been trained simply to rapid, clean cutting. It
has had to get its lumber and get it cheaply, and that is all there is
to it.

The forester, in cutting through our spruce woods, wants to
leave a stock for reproduction and growth. This, of course, can
best be left in the shape of young trees. No one is more interested
than the forester in removing, and so saving, all dead timber that
can still be used, and also any defective and declining trees.
Usually financial considerations will require much more to be taken,
probably two-thirds of all the merchantable timber. If so, the
forester is as interested as anybody in having that done thoroughly
and well. It must be done economically, however, without waste of
wood, and it must be done with as little damage as possible to the

FOREST MANAGEMENT IN MAINE. 69

young growth which it is desired to retain. And right here, in the
matter of saving and protecting the young trees to form a future
stock, is where the forester meets his difficulty, both with the men
he has in charge and with those who in turn are over him. The
way ordinary lumbermen rip, smash and destroy young trees makes
a forester sick to the stomach. And, on the other hand, the require-
ments imposed by his employers in respect to the amount of timber
that shall be taken, the form in which it shall be got out and the
expense of the operation make it often very difficult to do anything
effective for the land. Not the least of the obstacles encountered
is the logging boss. As a rule he is very efficient, but having up
to the present been a despot in his own domain he is often as
opinionated and self-willed an individual as can be met with.

Nothing will convey so clear an idea of the problem involved
as comparison and a brief record of experience. In the Adiron-
dacks, under the lead of Messrs. Pinchot and Graves, now of the
United States Foresty Division, large tracts of spruce land have
been taken in hand, carefully surveyed and examined, and cut-
ting w^ork has been begun in accordance with a carefully studied
plan. The ground to be cut through there is traversed the summer
before by the forester, and every tree that is to be cut is marked.
The cutting itself is very strictly supervised, and no departure from
the work marked out is allowed except for the strongest reason.
Lumbering methods in the Adirondacks differ somewhat from those
of Maine. There is less read cuttmg. Timber is cut into 13-foot
logs where it is felled, and dragged from the stump onto yards by
one horse. Now Pinchot and Graves state, in their volume, "The
Adirondack Spruce," that in this way they can take cut of the forest
just such trees as they want, and do practically no damage to the
remaining growth. A statement of what they found to be the aver-
age stand at Dr. Webb's Ne Ha Sa Ne park will make the matter
clear. For spruce alone they found 158 trees per acre under 2
inches in diameter, 75 trees 2 to 6 inches diameter, 37 between 6 and
10 inches and 31 trees 10 inches and over in diameter that would
scale about 3700 feet. In reference to these they state that the 31
trees per acre over 10 inches in breast diameter can be cut out and
yet leave practically all the 37 6 to lo-inch trees and the 233 of
still smaller sizes to form, as they would, a good growing stock on
the land.

In my experience of one year under conditions outlined above
no such results were attained as that. First, as accounting for
that, was the character of the timber stand. Here, for instance,
is the average stand of about 15 acres calipered over on one par-

70 ASSOCIATION OF ENGINEERING SOCIETIES.

ticular tract. Spruce over 4 feet high and under 6 inches in
diameter numbered here 64 per acre. Trees from 10 inches in breast
diameter, inchisive, down to 6 inches number 29, and would scale,
if cut, about 800 feet. Trees 11 inches and up in breast diameter
numbered 47 per acre, and would scale somewhere about 8000 feet.
We have here a larger amount of merchantable timber per acre than
in the Adirondacks. It is, however, due to size rather than to the
number of merchantable trees, while the number of small trees
ready to form the succeeding stand is far less than there. To the
landowner in consequence the grown timber is of more concern pro-
portionately than the small, and the forester's task of keeping the
land stocked is, outside of the natural disadvantages, rendered more
difficult.

Again, the forester's work was impeded by the business condi-
tions. The lumber cut on the tract I speak of was to be used, all
the largest and best of it, in the sawmill. It was essential, there-
fore, in order that it might saw to advantage in filling orders for
timber, that it be cut long. The logs were, in fact, cut as long as
could be driven out of the stream, 35-40 feet. When a tree would
make more than that it was sawed into two logs. Now the heavy
logs on rough ground required two horses, particularly as they
were not being bunched up into small yards for a wagon sled haul,
but being dragged often a mile or more directly to the river. Now
a road has to be cut out wide for two horses loaded with long logs
to get through, and many young trees in consequence are sacrificed.
Nor was that the only disadvantage. The weight of a big butt log
was heavy for men to handle. It could not be moved far, but trees
had to be laid in felling close to the road where the team could get
at them, while stuff had to be laid crosswise to roll it on and keep
it from bedding down in the snow. Thus in thick timber along a
road practically everything would be cut or smashed, and about all
that was left would be in the strips between. Much of this could
not possibly be helped under the conditions and within reasonable
limits of expense. It is often the case that the thinner stands are
left with the more promise of growth upon them.

Still, something could be accomplished, and that appears on all
accounts worth while. Setting a general size limit of 12 or 15
inches breast high, according to the stand, the crews would go
through a country cutting out the dead stuff and the larger timber
in a more or less bunchy fashion. On knolls and divides particu-
larly exposed to winds they would be required either to cut every-
thing or let everything stand. The ideal could not be accomplished
anvwhere. Some timber would be left above the size limit, some

FOREST MANAGEMENT IN MAINE. 71

that had no promise of growth in it. On the other hand, more than
a third of the small stuff would be cut or smashed down. This, of
course, would be hauled and used when large enough to be handled
without loss, but it was material which we should have preferred to
have grow. As a net result we would leave usually from 1500 to
3000 feet of growing timber on the land.

This is descriptive of a first attempt. In large measure it illus-
trates how not to do it. It is clear to me that if we are to do any-
thing worth while in forestry our organization in Maine must be
tightened up. This is necessary in order to accomplish the pur-
pose of forestry, to leave the land in good shape to grow, but I
believe it will pay on the score of simple economy of wood and labor.
In particular, if we are to leave our forests in shape to do their best
in the way of wood production, the choice of the trees that are to be
cut must not be left to ignorant and shifting choppers, btit the trees
must be marked beforehand by some one who understands the
methods and the purposes of the work. In my opinion the logging
boss and not the forester is the one who in the conditions of our
business here can best do that work.

In adherence to the main purpose of this address, I cannot
omit a brief reference to another and in itself a more attractive
branch of the forester's business, tree biology and the theoretical
grounding of forestry work. Take the matter of tree growth, for
instance, the measurement of producing capacity.

Each year's wood growth of a tree is deposited in a ring sur-
rounding on all sides its previous volume. The boundary of each
year's growth is usually w^ell marked, and the thickness can conse-
quently be measured. In practice it is better to measure the rings
in groups, say of ten each, beginning at the bark. The numbers of
rings, taken at several log-cuts along the length of a tree, give us,
with the diameter of each section, the means of computing the tree's
growth for the last decade or for any preceding period. That gives
us the individual tree. Hundreds of such computations, made on
trees of different thrift and size, allow us to average, and, taken in
connection with surveys of number and size of trees the country
over, enable us to estimate the growth in a valley or a township.

From the same observations inferences of great value are
drawn as to height growth. If a tree, at the ground, has 200
rings we know that it is, at least approximately, 200 years old. If
20 feet above ground we find 150 rings we know that the \'oung
tree consumed 50 years in growing to that height. So on up
through the number of sections.

72 ASSOCIATION OF ENGINEERING SOCIETIES.

The facts are best represented in graphical form. Thus a
spruce growing on a piece of burned land at Moosehead Lake was
cut down, leaving a stump a foot high. There were 98 rings in it.
Fifteen feet above there were 'j'j rings in the section, showing that
21 years were consumed in growing that height. Ten and one-half
feet higher there were 66 rings, and the same distance above 53.
The tree, as cut, was 65 feet high, and, allowing ten years of height
growth for the stump, it was grown in 108 years. These facts are
represented in curve i on the diagram, which will need no further
explanation.

The value of this method of representation will be best brought
out by comparison. Curve No. 2, for instance, represents the height
growth of a spruce which grew in the neighborhood of the other
tree, and in the same conditions, except those of soil. It was stand-
ing, in fact, on a bed of rocks. No. 5 is the curve of a white pine
which grew up with the first spruce, and was of the same age. It
shows the rapid production of that species.

Curves 3 and 4 are still more interesting. They represent the
growth of spruces which stood in mixture with hard wood in forest
whose history had been unbroken for centuries, which had trees of
every age and size. Young trees starting in such conditions have
to bear shade ; they grow slowly for many years, and only perhaps
after a century of struggle do their tops get out into free sunlight.
And the point is that our spruce can survive and retain its vitality
through a long course of such treatment. The tree represented by
curve No. 4, for instance, at 125 years of age was only 15 feet high,
and contained probably less than one cubic foot of wood. Yet, even
by that treatment, the vitality was not crushed out of it. Getting
finally free from suppression, it began a height growth equal to
that of young trees which never had been suppressed.

Now, study of our spruce timber shows that the bulk of it has
come to us through some such history as this. Knowledge of this
gives us an important rule for guidance in management. That is,
that young spruce in our woods, no matter if they are thin-crowned
and seedy looking, yet retain their vitality, and if in our cutting we
will at the same time protect them and open them to the light they
will reward us for it. This is one great advantage of our spruce.
The species is remarkable in this respect.

Last in this line I will present some figures on the volume
growth of spruce trees, illustrating what that is in percentage and
actual amount. The trees taken for observation ranged from 7 to
14 inches in breast diameter. They were 340 in number, and
observed results have been arranged and evened by drawing curves.

Breast

Volume

diameter.

of tree.

7 in.

6 cu. ft.

8 "

8

9 "

I0.5 "

lO "

14

II "

I7-S "

12 "

21.5 "

13 "

26

14 "

31

FOREST MANAGEMENT IN MAINE. yz

Inspection of the last column, the amount of yearly growth in wood,
shows that growth steadily increases as the tree grows larger ; that
up to the largest size here represented there is no slack. From this
point of view trees of this size are not ready to cut.

Growth of spruce on thrifty spruce land on the Kennebec
River, Maine, in volume and per cent. From third report of the
Maine Forest Commissioner:

GROWTH LAST TEN YEARS.

In diam., In per ct. at Yearly growth

inches, compound int. in cu. ft.

1.1 4.3 .26
I.I5 41 -2,2,
1-2 2>.7 .39
1-23 3-25 .45
1.23 2.9 .51
1.23 2.6 .56
1.22 2.4 .62

1.2 2.2 .68

The column next preceding shows the percentage that the
year's growth bears to the volume of the tree in the different sizes.
Here the course of the figures is the other way. According to the
table, a quarter of a cubic foot on a tree 7 inches in breast diameter
amounts to 4.3 per cent., while twice as much wood on a tree 11
inches through amounts to but 2.9 per cent. Here the forester is
checked by financial considerations. The larger he lets his trees
grow the smaller is the rate of interest earning on his capital.

Much might be brought out in this connection. I will draw
onl}' the practical inference that one prime object of the American
forester, who will be required to gain as rapid returns as possible,
must be to change over the stand as nature gives it to him, with its
large trees and comparatively small rate of accretion, into a thick
stand of smaller timber more quickly growing and reproducing.
That is particularly applicable to spruce when it is to be used in
paper manufacture.

For the present, however, all these matters will be secondary
in the mind of the working forester. Conditions vary through the
country, and everywhere investigation and instruction have their
field. But the man who, in conditions similar to those of Maine,
is bent directly on the task of bringing forestry actually to pass, will
endeavor to secure first the right financial conditions for his work,
and secondly to so organize woods work that it will carry out his
purpose toward the land in lines both simple and plain.

I wish to present one more topic, a topic of an engineering
nature. Men of your training do not have to be told that topog-
raphy determines very largely the course of all woods work.
6

74 ASSOCIATION OF ENGINEERING SOCIETIES.

Neither do you require to have explained the usefulness of a topo-
graphical map. Every lumberman is a topographer in a sense.
Clear knowledge of topography is essential to the man who, from
a central point, directs the conduct of a large business. So far in
the lumber business each man has learned his own topography by
cruising, and has carried it in his head. The limitations of this
system are evident. Such knowledge is inaccurate in the first place.
Then it is likely to be forgotten, and it cannot be conveyed to an-
other man. The loss is particularly evident when one manager
drops out of a business and his successor has to acquire his knowl-
edge of locality all over again.

In the autumn of 1896 I had the good fortune to be sent by the
Hollingsworth & Whitney Co., of Waterville, Maine, to make what
i suppose is the first genuine topographical survey ever made of a
New England timber township. The results, in the shape of a con-
tour map and a model, proved so much of a satisfaction to the com-
pany and its superintendent that other concerns were led to desire
the same thing. Thus I have been employed to survey in all about
125,000 acres. I think, furthermore, that in the economy of the
spruce forests of New England topographical mapping has come to
stay. A brief description of the methods employed in this work,
developed as they have been in the work itself, with the aid of such
hints and helps as could be got from outside, may be of interest to
members of the Society.

The basis of the height work is leveling. If possible, connec-
tion is made with points known from railroad levels or otherwise,
giving thus elevation above sea; then a line of levels is run over
roads, or whatever else may be the best route to run on, to the
ponds and other suitable marks well distributed through the town-
ship to be surveyed. From the points so determined by level I
work off with aneroids, returning for correction as often as may
be to some accurately known point. Two aneroids are usually car-
ried ; a thermometer is read with them as often as necessary, and
changes of pressure due to the weather are recorded meanwhile by
a barograph run by an eight-day clock located at the main camp.

The low accuracy of aneroid measurement is well known, but
when carefully used with the aid of the accessories noted above, the
aneroid suffices entirely for the purpose. A timber land manager
does not require to know, for instance, exactly how high a given
mountain is. The approximate relation of things is what he wants.
The areas of valleys, the positions of streams and divides, the shape
and steepness of the land, the grade of future roads, — these are
essential points. Then the passes and their neighborhood often

FOREST MANAGEMENT IN MAINE. 75

require especial looking over, because it is sometimes very desirable
to haul timber from one drainage to another, if that can be done
without too much uphill work. In getting at all these points a
land level has frequent use, in addition to the aneroid, or, better
still, an Abney clinometer.

In these surveys the land has ordinarily been blocked up ahead
of me into mile squares. It is a great advantage if, when the lines
were run, marks were left v,very quarter-mile. Then one can locate
himself quite accurately on a line by pacing and without going very
far. These marks serve also as the starting point in examining the
interior of a lot. For instance, after having traversed the lines of
a lot, noted the crossing of brooks and divides, taken the height of
essential points and noted or sketched whatever topography could
be seen, I might start from the middle of one side to run a line
across the lot. In doing this I often use a staff compass with 3-inch
needle and folding sights, but perhaps more frequently a common
pocket compass with needle less than 2 inches long held in the hand.
Indeed, direction can sometimes be held more closely with the
latter instrument. For instance, a man climbing over the debris
left by cutting or shoving his way, head down, through dense
thickets of young fir loses direction in the course of a few rods.
Now if he has a compass in hand he will stop and look at it. He
will do so less often if he has to set a staff, level his instrument and
wait for the needle to come to a stand.

Meanwhile distance is kept by counting steps. Six or seven
years ago, when I first tried to keep run of distance in this way, in
retracing old woods lines, I found I required about 2400 steps to
the mile. Later on, either because with practice I became longer
gaited or because, without knowing it or meaning to, I discounted
more, the number required became less. I found at one time that
I was using 2200, and finally I got down to 2000 to the mile. There
I expect and desire to stay, because at that rate notes plot so readily.
In field sketches and in final maps I have so far used a scale of 4
inches to the mile. On that scale, at 2000 steps to the mile, 100
steps are two-tenths of an inch, and a half-inch square, or a piece
of ground 250 steps on a side constitutes 10 acres.*

By one who has practiced it, measurement by pacing can be
made, even in rough land and bad walking, much more accurately
than would be supposed. One travels along, looking at the coun-
try, keeping his count in some back corner of his mind. Every

*Much help has been received on this and other points from the methods
of the U. S. Geol. Survey in Michigan and Wisconsin, as communicated by
Prof. W. S. Bayley, of Waterville, Maine.

■ 76 ASSOCIATION OF ENGINEERING SOCIETiES.

hundred passed is marked down or scored by breaking an elbow in
a tough twig carried in the teeth or hand. When a brook is passed
or a change in the land occurs note is taken, the barometer read and
the count begins again. Steps taken to get round obstacles are
not counted, and on strong slopes discount is made. On very
steep ground, indeed, steps taken are not a guide to distance, and
judgment has to be resorted to in order to fill in the count. As
first remarked, however, long practice enables a man to reach
greater accuracy than would be supposed. Thus I am seldom out
over lOO steps from the 2000 in crossing a lot. The count tells
me when a line is approached, and enables me to pick it up with cer-
tainty, though it may be blind. Then I go right or left till I hit a
quarter-post, and so ascertain the variation from the true compass
course. By this means locations are made with considerable
accuracy along the whole line.

What has been said makes it evident that a pedometer in just
this kind of work can have but little use. It answers very well in
smooth going, but its readings are no guide to distance on rough
land. In my work it has been used merely as a matter of interest
to estimate the number of miles traveled in a day or on a whole job.
It is, in fact, a good deal of satisfaction after cruising a rough town-
ship, perhaps half-covered with brush heaps and blow-downs, to
figure up and tell the company just how far I have been.

On simple ground running once across a lot serves, with a
traverse of its boundaries, to give topography sufficient for the pur-
pose. Elsewhere there are roads and streams to locate and divides
that should be carefully put in. Here compass and pacing are still
used, tying in to the lines as often as may be. Travel in parallel
straight lines, however, has advantages if it is sufficient for the
immediate purpose in hand. It is more accurate, in the first place.
Secondly, if, as will no doubt be usual, the timber land topographer
also understands timber, and is expected to report on its character
and amount, systematic travel of this kind insures his seeing a fair
sample of all the land. Timber estimates in the past have been
notoriously inaccurate and misleading in their results, and one great
cause of this has been that the men who made them did not see all
the land. Of the accessible parts, perhaps of the good parts, they
saw too much. They did not fairly balance the whole or correctly
allow for the waste land. One man of my acquaintance, realizing
that fact, says that in looking over land for purchase he makes it a
practice to go first where no timber is to be found. Better than that
is some systematic arrangement that causes one to see a sample of
everv part, and travel in straight lines evenly spaced will do it.

FOREST MANAGEMENT IN MAINE. ^^

So far our maps have been constructed on the scale of 4 inches
to the mile, and 50-foot contours in the rough land with which we
have to deal serve to represent the topography. In addition, as a
result of the examination, timber maps are constructed showing
the character of the growth and the amount of merchantable timber
judged to be standing on the land. On these sheets the progress
of the cutting can be drawn in succeeding years. These timber
maps are of transparent tracing cloth, so that they can be laid
over the topography and the two seen in relation. Lastly, since con-
tour maps are not easily read by most woodsmen, topographical
models are constructed out of cardboard or veneer. These are
perfectly comprehended by any person. With their aid a contract
can be let or plans of work talked over in the office with the same
clearness as to main features as if men were on the land.

The survey and mapping of a township six miles square has
ordinarily cost me about two months' work, two weeks in the office
and six in the field. A township can be gone over conveniently
from about four camps. _ If there are on the land places to live in
the topographer requires the help of but one man.

78 ASSOCIATION OF ENGINEERING SOCIETIES.

POWER DEVELOPMEN^T AT NIAGARA FALLS OTHER
THAN THAT OF THE NIAGARA POWER CO.

By W. C. Johnson, Member of the Engineers' Society of Western

New York.

[Read before the Society, February 3, 1896.]

Within the past five years a company has been engaged in the
development of water power at Niagara Falls, about whose opera-
tions much has been said and written.

The plan which this company was organized to carry out in-
volved the construction of a long tunnel under the city for a tail-
race, and the sinking of shafts into the rock to a depth of 150 to
175 feet in which to place its wheels.

This work was necessarily costly and many difficult problems
arose in its execution.

The problems have been solved and the work executed in a
manner which reflects great credit upon the eminent engineers who
have made up the consulting board, and upon the able engineers
who have had charge of the execution of the different parts of the
work.

Those of us who have followed the progress of the work, as
most of us doubtless have done, I imagine scarcely know whether
to admire most the good judgment shown in the employment of
engineering talent or the wonderful skill in advertising. The
newspaper fraternity have turned themselves loose on this work.
The adjectives "vast," "grand," "stupendous," etc., have been liber-
ally thrown into every item, but not always with discretion.

One of the most glaring absurdities in connection with the
mass of popular writing about this work has been the use of the
phrase "Harnessing of Niagara," and the statements, in big head-
lines, that power would be turned on at Niagara on a certain date
( which date was, by the way, several times changed), when the facts
are that at the time when the first shovelful of earth was taken out
in this work more water power was in use at Niagara Falls than in
but few other places in the world, and by far the most powerful
wheels in the world were in operation there.

Power at Niagara was turned on in 1725, and, during most of
the time since, its force has been utilized to turn water wheels.

It is to these other and earlier developments that I will call
your attention to-night.

The first use of power at Niagara was about 1725, when the

POWER DEVELOPMENT AT NIAGARA FALLS. 79

French erected a sawmill, near the site of the Pittsburg Reduction
Company's upper Niagara works, for the purpose of supplying
lumber for Fort Niagara.

In 1805 Augustus Porter built a sawmill on the rapids. In
1807 Porter & Barton erected a grist mill on the river. In 1817
John Witmer built a sawmill at Gill Creek. In 1822 Augustus
Porter built a grist mill along the rapids above the falls. From
that time to 1885, when the lands along the river were taken for a
State Park, a considerable amount of power was developed along
the rapids by a canal which took the water out of the river near the
head of the rapids and followed along nearly parallel with the bank
of the river.

Mills were built between this canal and the river and a part of
the 50-foot fall between the head of the rapids and the brink of the
falls was utiHzed. A paper mill was also built on Bath Island.

In 1847 Augustus Porter outlined the plan on which the present
Hydraulic Canal is built.

In 1852 negotiations were commenced by Mr. Porter with
Caleb J. Woodhull and Walter Bryant, and an agreement was
finally reached with these gentlemen by which they were to con-
struct a canal and receive a plat of land at the head of the canal
having a frontage of 425 feet on the river ; a right of way 100 feet
wide for the canal along its entire length of 4400 feet, which is
through the most thickly populated part of the city, and about 75
acres of land near its terminus having a frontage on the river
below the falls of nearly a mile.

Ground was broken by them in 1853, and the work was carried
on for about sixteen months ; it was then suspended for lack of
funds, and nothing more was done until 1858, when Stephen N.
Allen took up the work and carried it forward for a time.

After that, Horace H. Day took up the matter, and in 1861
completed a canal about 36 feet wide and about 8 feet deep.

The location of the head of this canal was the best that could
have been chosen. From the head of the rapids it is but a short
distance to an island (Grass Island), which extends a considerable
distance along the shore, and for a considerable distance above the
island the water is very shallow.

In this short space, between the head of the rapids and the foot
of Grass Island, the entrance of the canal was located.

Owing probably to the disturbed financial conditions occa-
sioned by the War of the Rebellion, and other causes, it happened
that no mills were built to use the water from the canal until 1870,
when Mr. Charles B. Gaskill built a small grist mill on the site of

80 ASSOCIATION OF ENGINEERING SOCIETIES.

the present flouring mill belonging to the Cataract Milling Com-r
pany, of which Mr. Gaskill is president.

In 1877, the canal and all of its appurtenances were purchased
by Mr. Jacob F. Schoellkopf and A. Chesbrough, of Buffalo, who
organized the Niagara Falls Hydraulic Power and Manufacturing
Company, of which Mr. Schoellkopf is still the president.

Since that time the building of mills has gone steadily forward.
The following is a list of the mills using water from the canal :

Central Milling Company use 1,000 horse power.

Schoellkopf & Matthews use 900 " "

Pettebone-Cataract Paper Co. use 1,300 " "

Cataract Milling Company use 400 " "

T. E. McGarigle, Machine Shops, use 12 " "

City Water Works use 155 " "

Pittsburg Reduction Company will use 3,000 " "

Cliff Paper Company use 2,500 " "

Will use in 1896 additional 300 " "

Niagara Falls Hydraulic Power and Manufacturing Com-
pany, use 280 " "

Rodwell Manufacturing Company, Niagara Silver Com-
pany, use 75 " "

Carter Crume Company use 39 " "

Francis Manufacturing Company use 10 " "

The Kelley-McBean Company use 5 " "

Oneida Community Co., Limited, use 300 " "

Niagara Falls and Lewiston Railroad use 150 " "

Will use in 1896 additional 350 "' "

Niagara Falls Brewing Co. will use in 1896 250 " "

Total 1 1,026 " "

Mr. Porter's contract with Woodhull & Bryant only conveyed
the lands to the edge of the high bank of the Niagara River, and
did not include the talus or slope between the edge of the high bank
and the river, and only granted the right to excavate down the face
of the bank 100 feet.

At that time it was not considered that any higher head could
ever be utiHzed, because it was not thought that wheels could be
built to stand the pressure of a higher head ; in fact, none of the
mills attempted to use more than 50 or 60 feet head. For this
reason it happened that although the capacity of the canal as at first
constructed was sufficient for some 15,000 horse power its capacity
was exhausted and only about 7000 horse power produced.

The flouring mills of Schoellkopf & Matthews, Cataract Mill-
ing Company, Central Milling Company, the Pettebone-Cataract
Paper Company, the City Water Works, and the factory of the
Niagara Wood Paper Company, which is not now running, leased

POWER DEVELOPMENT AT NIAGARA FALLS. 8i

the right to draw certain quantities of water from the canal and
constructed their own wheel pits, and put in their own water wheels.

Two different methods were adopted for constructing the pits
for these various mills. In some cases a shaft was sunk in the rock
at some little distance back from the edge of the bank, in which the
wheels were placed, and a tunnel driven from the bottom of the
shaft to the face of the bank for the discharge of the water after
it had passed the wheels. In other cases a notch was cut into the
face of the bank and the wheels placed in it.

In all cases turbine wheels of different makes, running on a
vertical axis^ were used.

In 1 88 1 the Niagara Falls Hydraulic Power and Manufactur-
ing Company put in a power plant for the purpose of supplying
power to customers, delivered into their mills. The method adopted
was as follows :

A shaft 20 X 40 feet was sunk to a depth of about 80 feet, and
about 200 feet back from the face of the high bank ; from the
bottom of this shaft a tunnel was driven to the face of the bank for a
tailrace. The water was conducted to the bottom of this shaft in
iron tubes, and used on two different turbines running on vertical
axes.

The power developed by these wheels — about 1500 horse power
— w^as transmitted by shaft, belting or rope drive to various cus-
tomers, all located within 300 feet of the wheel pit.

About a year ago a turbine wheel of a capacity of 600 horse
powder, running on a horizontal axis, was put in this same wheel
pit, the power transmitted up to the surface by meafis of a manilla
rope drive, and there used to run electric generators, from which
power is being transmitted to various small consumers.

In 1886 the Niagara Falls Hydrauhc Power and Manufactur-
ing Company secured a deed of portions of the slope between the
high bank and the river, and have since secured other portions, so
that they are now at liberty to use this slope for mills and power
houses. In this same year I was appointed engineer of the com-
pany, and have been in charge of all the improvements made since
that date. /^

The advance in water wheel construction, and especially the de-
velopment of the possibility of transmitting power by electricity,
has made this lower slope one of the most valuable parts of their
holdings.

In the spring of 1892 the Cliff Paper Company, being desirous
of increasing their plant by adding a wood pulp mill, to use about
2500 horse power, leased sufficient water from the Niagara Falls

82 ASSOCIATION OF ENGINEERING SOCIETIES.

Hydraulic Power and Manufacturing Company, agreeing to take
it from the tunnel through which water was discharged from the
outlet of wheel pit just described, and I was employed to design and
superintend the construction of the plant.

For the purpose of getting the machinery requiring the largest
power near to the wheels, it was decided to build a mill on the lower
bank near the water's edge, and to place the pulp-making machinery
in it, preparing the wood on the top of the bank, lowering it down
ready for grinding and elevating the product.

To divert the stream of water flowing through the tunnel and
confine it for use in the new mill, a short tunnel was driven into the
face of the bank at a point about 20 feet below and 12 feet to the left
of the mouth of the old tunnel.

From the mouth of the new tunnel an iron pipe 8 feet in
diameter was laid along the slope of the bank, connecting with the
tube 10 feet in diameter in the basement of the lower mill. From
this tube the water is brought to the wheels on the first floor. Pro-
vision is made for the discharge of water into the tunnel direct
from the canal in case the discharge from the wheels does not fur-
nish a sufficient supply.

Owing to the contracted channel of the river below the mill,
there is an extreme fluctuation in the water below of about 30 feet,
and it is liable to sudden changes. On this account the first floor,
on which the wheels are placed, is set about 16 feet above the ordi-
nary level of the water in the river, which is above the highest
recorded rise, the remaining part of the head being obtained by the
use of draft tubes.

It was decided to use two wheels to develop the required
2500 horse power and to couple the shaft of the water wheel to the
shafts carrying the stones used for grinding the wood.

It was therefore necessary that the wheels should run at a
speed of 225 revolutions per minute. This requirement, as well
as the requirements of strength, precluded the use of any of the
stock wheels in the market and made a special design necessary.

Under my plans and specifications the wheels were built by
James Leffel & Company, of Springfield, Ohio.

The wheel runners are 66 inches in diameter. The bucket
rings are made of a special quality of bronze. These rings are
fitted to a heavy cast iron center with steel bolts ; each ring supplied
with twenty-four buckets, with the discharge opposite each other.
The wheel runner is fitted substantially with keys to the wheel shaft,
which is made of hammered wrought iron, finished diameter
through bearings 6| inches, with a total length from center to

POWER DEVELOPMENT AT NIAGARA FALLS. 83

center of couplings of 17 feet. In order to prevent the wheel shaft
from shifting endwise, suitable adjustable collar bearings are
located on it, immediately on the inside of the elbow.

Surrounding the outside of the wheel runner are wheel cylin-
ders, supplied with twenty gates. These gates are made of cast
steel and designed to be as nearly balanced at all points of the gate
opening as possible. They are mounted on steel gate bolts attached
to wheel cylinders. Each gate is supplied with two side-rack arms,
which arms are attached loosely to the two side-rack rings. These
rings are mounted on the wheel cylinders, and are operated simul-
taneously by the movement of the gate shaft connecting to them
with roller rings made of cast steel. The gate shaft is made of
hammered wrought iron, passing through bronze stuffing boxes in
the sides of the cylindrical case. One end of this gate shaft is
operated by a suitable lever, with bronze nut, steel screw and hand
w^heel for same, carried in the heavy frame mounted on one of the
elbows.

The work is contained in a cylindrical case 10 feet in diameter
by 4 feet wide. The heads are made of heavy cast iron, with
f-inch steel shell solidly riveted to them. On the top of the case
is a large air chamber to assist in equalizing any irregularities in
the flow of the water to the wheel. This air chamber is supplied
with an air pump and glass water gauge, so that it can be cleared
properly and filled with air when necessary. The case is also
fitted with manholes and plates.

On the side of the case elbows are fitted, which are made of
cast iron, being split through the center and bolted together, and
where the wheel shaft passes through the elbows are stuffing boxes
with bronze glands. Each elbow is fitted with manholes and plates.

On the discharge end of the elbows are fitted draft tubes which
are each 18 feet long, made of ^-inch steel thoroughly riveted and
calked throughout. These draft tubes are substantially anchored
to the foundation walls to prevent breaks or leakage by any move-
ment. The wheel shafts, after passing through the elbows, are
carried in heavy flat bearings, each 24 inches long, lined with anti-
friction metal, bored to fit the shaft and supplied with ring oiling
attachments, with large capacity of oil chambers at each end and
on bottom sides of the bearings. The bearings are mounted on
hea\y cast iron bridge-trees, and are supplied with suitable bolts
and adjusting screws, making a distance of 4 feet from the center
of the wheel shaft down to the top of the steel beams.

The work is mounted on four heavv 20-inch steel beams, of

(

84 ASSOCIATION OF ENGINEERING SOCIETIES.

suitable strength and proportion for spanning the foundation walls,
which are 14 feet 6 inches in the clear.

In 1892 the Niagara Falls Hydraulic Power and Manufactur-
ing Company commenced an enlargement and improvement of its
canal. The plan adopted was to widen the original channel to
70 feet and make the new part 14 feet deep. The canal is cut
entirely through rock below the water line.

The power for driving the drills on this work was obtained
from an air compressor run by water power from the power station
and transmitted along the line of the canal in pipes. The excava-
tion was done by dredges and the flow of water through the canal
was not interfered with.

This improvement is now completed, and the canal has a ca-
pacity of about 3000 cubic feet per second, giving a surplus power,
after supplying the old leases, of about 40,000 horse power.

Since this improvement has been completed a new power house
has been commenced for the purpose of supplying power for
tenants.

For this new plant water will be taken in an open canal from
this hydraulic basin to a forebay 30 feet wide and 22 feet deep,
which is now being built near to the edge of the high bank. From
this forebay penstock pipes built of flange steel, 8 feet in diameter,
conduct the water down over the high bank 210 feet to the site of
the power house on the sloping bank at the edge of the water in the
river below the falls.

The site of the power house was covered with broken and dis-
integrated rock which had fallen from the bank during ages past,
which covered the bed rock to a depth of from 10 to 70 feet.

For the removal of this loose material a Giant or Monitor, as
it is termed, was used. This is a machine throwing a stream of
water from 4 to 6 inches in diameter, according to the size of the
nozzle used, under pressure. It is very largely used in the Western
part of the United States for mining purposes.

The water to supply this machine was taken from the canal,
and the pressure of 210 feet head fall was sufficient to give a force
Avhich readily washed down all the loose material into the river,
uncovering a bed of sandstone upon which the power house is built,
and from which the material of which it is built was quarried.

The power house building will be 180 feet long by 100 feet
wide, and will contain sixteen wheels of about 2000 horse power
each. Only one-third of the length of the building is being con-
structed at present, it being intended to add to it as the demand for
power arises.

POWER DEVELOPMENT AT NIAGARA FALLS. 85

The wheels in this power house will work under a head of 210
feet, which is the highest head under which water has ever been
used for power in the quantity proposed in this plant.

The wheel which has been most used in the United States under
high heads is the Pelton wheel, which is an impact wheel running
on a horizontal axis. The use of the Pelton wheel was deemed in-
advisable in this plant, because on account of the fluctuation of the
water in the lower river, which is as much as 30 feet, it was neces-
sary to place the floor of the station on which the generators were
to stand about 20 feet above the ordinary water level, and, as it was
desired to couple the generators directly to the end of the water
wheel shaft, it was necessary to place the water wheels also at this
elevation. This necessitated the use of draft tubes in order to
obtain the full head available, which is impossible on the Pelton
wheel.

It was necessary that the wheels would run at a given speed
suited to the speed desired for the generators.

All of these conditions could not be met by any other construc-
tion than the turbine wheel, mounted on horizontal axes.

It was decided that water for the wheels should be supplied by
a penstock leading from the forebay above described, vertically,
about 135 feet to the top of the sloping bank, thence down the
slope to the side of the station next to the bank, 8 feet in diameter,
connecting wnth a supply pipe 10 feet in diameter, running horizon-
tally along the center of the tailrace, from which the wheels would
draw their w^ater by connections from the bottom of the wheel case
to the top of the supply pipe. In this connection, which is 5 feet
in diameter, valves are placed so that any wheel can be shut down
independently of the others. The wheels standing directly over
this trunk discharge the water through draft tubes running down
on either side of the supply pipe.

Several reliable builders of water wheels were asked to design
wheels from my general plans and specifications, of which the fol-
lowing are the more important points :

"The wheels to be furnished under these specifications shall be
horizontal in form, and figured to furnish 1900 horse power,
measured on the shaft of the wheel, and to run at a speed of 300
revolutions per minute.

"The head under which these wheels will work will generally
be 210 feet, but the wheel shall be figured of sufficient capacity to
deliver 1900 effective horse power under a head of 205 feet, and
all parts shall be of sufficient strength to stand the pressure due to a
head of 220 feet without undue strain.

86 ASSOCIATION OF ENGINEERING SOCIETIES.

"The wheels shall be designed to take water directly under-
neath the bottom of the case at- the center, and shall be provided with,
a supply pipe of such length as shall be specified on drawings here-
after to be furnished, which shall not exceed 2 feet below the
periphery of the case.

"The case shall be supported on four 20-inch steel beams
weighing 80 pounds per foot and 21 feet 6 inches in length.

"To these beams all the bridge-trees and the case shall be fitted
and fastened.

"The beams shall be set such a distance apart and carrying
the case so that the center of the shaft shall be at such a height
above the top of the beams as shall be specified upon drawings to
be hereafter furnished.

"The contractor shall guarantee all parts of the wheel to be of
sufficient strength to stand the strain as above specified.

"He shall further guarantee the wheel to furnish 1900 effective
horse power, measured on the shaft of the wheel when working
under an actual head of 205 feet, and running at a speed of 300
revolutions per minute.

"He shall further guarantee the wheel to show a percentage
of useful effect of not less than 78 per cent, at any point between
full and three-quarters water under any head from 205 feet to 225
feet, and running at a constant speed of 300 revolutions per minute.

"He shall further guarantee a percentage of useful effect of
not less than 60 per cent, under the same conditions from three-
quarters to one-half water."

Under these specifications a contract was let to James Leffel &
Co., of Springfield, O., for supplying the four wheels to be put in
at present. The description of the wheels is as follows :

The wheel runners, in case of three wheels which are to run
the generators of the Pittsburg Reduction Company, and which
are to run at a speed of 250 revolutions per minute, are 78 inches
in diameter ; in case of the other wheels, which are to run at 300
revolutions per minute, 66 inches, the size being calculated so that
a point in the periphery of the runner will move at a speed equal to
about 75 per cent, of the theoretical velocity of water, due to the
head under which the wheels are operating.

The rim of the runner is the bucket ring, and is cast solid from
gun metal bronze. On this rim are two sets of buckets taking
water on face and discharging at each side of the rim. The bucket
ring is bolted to the spokes of a cast iron center, the hub of which'
is keyed to the shaft of hammered iron 20 feet in length.

Surrounding the outside of the runner is a cylinder in which'

POWER DEVELOPiMENT AT NIAGARA FALLS. 87

the gates are fitted. The gates are about 20 per cent, less in num-
ber than the buckets. They are hung on steel pins, and open by
lifting one edge so that the direction in which the water enters the
wheel is nearly tangential to the runner.

Each gate has two arms, which are connected to the rings, by
means of which they are opened and closed.

This work is inclosed in a cylindrical case ii feet in diameter
and 4 feet long, which is connected to the penstock by a supply tube
5 feet in diameter.

On the side of this case elbows are fitted, to which the draft
tubes are connected. The shaft passes out through these elbows
through stuffing boxes. On the inside of these elbows lignum vitae
steps are fastened, against which rings on the shaft work to prevent
end motion in the shaft.

To each end of the water wheel shaft will be rigidly coupled a
direct current generator, capable of developing 560 kilowatts of
electrical energy.

The beams upon which the wheels stand will be extended
through underneath the generators, the whole to be fastened to-
gether and bolted firmly to the masonry foundations.

It is probable that regulation of speed will be secured by the
following described device, though it is not fully decided :

The apparatus for regulating the speed of the wheels consists
of a hydraulic piston, which applies its force in either direction to
a rack which is connected with a pinion in the gate rigging of the
turbine.

The force which operates the hydraulic piston is air, com-
pressed under about fifteen atmospheres.

This compressed air is contained in a cylinder directly under
the bed of the machine, and the pressure is maintained by a pump
which constitutes part of the machine.

The pressure tank is about one-third full of a fine oil, and the
piping is such that oil and never air enters the hydraulic cylinder.

There is a partition in the pressure tank, and one part of the
tank is filled with oil and air under the pressure of fifteen atmos-
pheres, and the other part of the tank is a vacuum.

After the oil has expended its force on the horizontal cylinder
it is discharged into the vacuum end of the tank, and by the pump
transferred into the pressure end. In this way a constant pressure
and a constant vacuum are maintained. In other words, the oil
circulates under pressure in a closed system without any access to
atmospheric pressure.

The machine is provided with a high speed ball governor,

88 ASSOCIATION OF ENGINEERING SOCIETIES.

which actuates a balanced piston valve which stands in the circu-
lating system. This valve has a lap 1-64 of an inch, and a motion
of that moved one way or another as the speed varies throws the
oil under pressure into one end or the other of the hydraulic cylin-
der, causing the rack to move so as to open or close the gates of the
turbine, according as the speed is rising or falling.

The governor has an appliance by which the governing
machine is checked before it has carried the gate too far open or
shut, thus preventing racing, which has always been the difficulty
with most machines devised for regulating the speed of water
wheels.

The electric current generated in this power house will be con-
ducted to the top of the high bank by copper conductors, carried up
through an inclosed wire tower, and from thence distributed to the
various consumers.

DISCUSSION.

Mr. Bassett. — Why is it necessary to place the wheels so far
above the water level in the river and use draft tubes ?

Mr. Johnson. — Because of the rise in the river during storms,
which is sometimes as much as 30 feet ; that is to say, the total
variation between the extreme high and the extreme low water in
the river below the falls is liable to be as much as 30 feet; that is,
the water level is liable to vary as much as 15 feet either way from
the ordinary level.

Mr. Bassett. — Why should there be such a rise at the falls
when the rise at Buffalo is only about 5 feet during a storm ?

Mr. Johnson. — The narrowness of the river below the falls
near the Cantilever Bridge chokes the flow and causes the rise.
The rise at Port Day, where the canal intake is, just above the
rapids above the falls, is from 5 to 6 feet. The river at that point
is probably a mile wide.

Mr. T. Guilford Smith. — What is the total amount of power
proposed to be developed by the power companies at Niagara Falls
by the plans now being carried out ?

Mr. Johnson. — The tunnel already built by the Niagara
Power Company has a capacity of about 100,000 horse power.
They have the right to draw water from the river to the amount of
200,000 horse power, and I believe contemplate the possibility of
constructing another tunnel. The present capacity of the canal of
the Niagara Falls Hydraulic Power and Manufacturing Company
is about 50,000 horse power, and can readily be increased to 100,000
or 200,000 horse power.

POWER DEVELOPMENT AT NIAGARA FALLS. 89

Mr. Smith. — What is the present capacity of your canal?

Mr. Johnson. — About 3000 cubic feet per second. If the
canal were to be deepened this could be very materially increased.
The canal is capable of development up to 100,000 horse power, or
even 200,000 horse power.

Mr. Guthrie. — What is the estimated quantity of water that
will be taken from the falls by these two plants when completed ?

Mr. Johnson. — The grant to the Niagara Power Company
says, "Water sufficient to produce 200,000 effective horse power."
This language is, about as definite as would be a deed of sufficient
land to raise a certain number of bushels of corn annually. I sup-
pose this grant would probably be construed to mean somewhere
from 13,000 to 13,500 cubic feet per second.

The Niagara Falls Hydraulic Power and Manufacturing Com-
pany is at present using something like 1000 cubic feet per second,
and if its plant should be increased to 200,000 horse povv^er would
use from 11,000 to 12,000 cubic feet per second.

Mr. Guthrie. — What effect will that have upon the falls ?

Mr. Johnson. — The drawing from the river of the extreme
quantity mentioned, it is estimated, would reduce the depth of
water on the American falls about 3 inches, and on the Canadian
falls about 11 inches. It is- not likely, however, that this extreme
quantity of water will be used for the next one hundred years or so,
and, even if it should be, the slight changes in the depth would be
immaterial when it is remembered that the difference in the direc-
tion of the winds is continually making a difference from day to day
of some 3 to 6 feet.

Mr. Smith. — Are there not times now when the rocks in the
river above the falls are out of water which at other times are
covered ?

Mr. Johnson. — Yes, sir; frequently.

Mr. Rogers. — Why did you say Pelton wheels were not
adopted for your plant ?

Mr. Johnson. — By using them we would lose about 16 feet
of the head, as draft tubes cannot be used with Pelton wheels.
This is the reason why the use of Pelton wheels was not seriously
considered in this plant. I would not be understood to say that
the Pelton wheels are necessarily the best for such a plant as this
if it were not for the necessity of the use of the draft tube. The
Pelton wheel is the only wheel which has been used successfully
under extreme heads of, say, 500 to 1500 feet. Under 200 feet head
I am not at all sure that the turbine wheel is not as good or better
than the Pelton.

90 ASSOCIATION OF ENGINEERING SOCIETIES.

A Member. — Will the mills that take water from the canal
continue to do so after the new plant is completed, or will they use
electricity ?

Mr. Johnson. — They will probably continue to run as they do
now. This electric power is intended for supplying new consumers.

A Member. — What is the capacity of the power plant you are
now building?

Mr. Johnson. — 7000 horse power at present, with a contem-
plated increase to 20,000 or 25,000 by an extension of the same
station.

A Member. — Where are the wheels being built?

Mr. Johnson. — By the Jas. Leffel Wheel Company.

Mr. McCulloh. — Have you any data upon the cost of exca-
vating by the hydraulic excavator you used in preparing the foun-
dation for the new power house?

Mr. Johnson. — I am not able to state the exact cost at present,
as it was all day's work, done by the power company itself.

PAVING BRICK AND BRICK PAVEMENTS. gi

PAVING BRICK AND BRICK PAVEMENTS.

By H. J. March, Member of the Society.

[Read before the Engineers' Society of Western New York, November 9,

1896.]

HISTORY.

Brick have been in use in one form or another for a great
many centuries. It is recorded that in 2247 B.C. the descendants
of the sons of Noah said : "Go to ! Let us make bricks and burn
them thoroughly."

The Tower of Babel was built of well-burned brick. The mud
of the Nile was the only material in Egypt suitable for brickmaking.

The plan was to make a bed into which were thrown large
quantities of cut straw, mud and water, and this was tramped into
pug, removed in lumps and shaped in molds by the hands. The
molded clay was sun-dried, not burned, the bricks of Egypt being
adobes. Contrasting this mode with that of to-day, it seems very
crude indeed. Bricks, burned and unburned, were employed to
some extent in the construction of the Great Wall of China, com-
pleted in 211 B.C. The credit of first burning bricks in kilns prob-
ably belongs to the Romans ; but it is hard to fix the time of this
improvement. The knowledge of the art of brickmaking has
probably at no time become entirely extinct; but with the decline
of Roman civilization it gradually expired, and was lost in Western
Europe. The Romans made bricks extensively in Germany and in
England.

During the reign of Henry VI brick construction was not very
general, but under Henry VIII and Elizabeth the brick industry
grew extensively. The fourteenth century did not see much brick-
work construction, but in the fifteenth brickwork became common.

Up to the seventeenth century bricks made in England were of
variable sizes. Charles I, in 1625, regulated the size considerably,
and made them nearly uniform. In Holland and other provinces
of the Netherlands, where no stone, except of inferior quality, is
found, brick have been of universal use from the earliest times, the
paving of streets and other public works being done with them.
Hard paving bricks were made from a mixture of slime from the
Haarlem Meer and sand. The celebrated Dutch Clinkers, or pav-
ing brick, were made at Moor from the slime of the River Yessel.
In this country the New Haven colony was the earliest settlement
in which brickmakers were recorded as a part of the population, and
it is probable that in 1650 the first bricks made in this country were

92 ASSOCIATION OF ENGINEERING SOCIETIES.

burned by this colony. Brickwork became common here about
the eighteenth century. Improvements in modes and machines for
making common bricks received but Httle attention prior to 1840.
Very Httle care was paid to the brick after they came from the kiln,
the whole idea being to shape or mold them in some way. Conse-
quently the bricks were light and porous, and absorbed a large
amount of water; but modern brick machines have lessened
materially these objections. We find bricks were first used for
paving in this country about 1870, at Charleston, W. Va. This
brick was simply common building brick, burned hard, resting on
a board foundation. From this first use of hard-burned common
brick for street pavement there has gradually grown the vast paving
brick industry, common in our Western States particularly, fos-
tered by the demand for a cheap, as well as a durable, pavement.

[ CLAY.

Paving brick in general are made from fire clay or shale, or
both. The term clay is applied to the hydrous silicates of alumina,
and has been produced largely by the decomposition of felspar
rocks, caused probably by water disintegrating the binding material.
The rocks containing a good proportion of oxide or salts of iron
forming red clays, and those having but traces forming white or
light clays. Pure clay has been found to be infusible even in the
most intense heat, but when mixed with the alkalies or alkaline
earths it becomes fusible in proportion to the admixture. Clays
possessing a high degree of plasticity are termed long or fat, but
when having little plasticity are termed short, meager or lean. In
the parlance of the brickyard the first is called "strong clay" and the
latter "weak clay." Strong clays absorb considerable water in
tempering, and bricks made from these clays shrink materially in
drying and burning. On the contrary, weak clays absorb but little
water, and do not shrink either in drying or burning.

There are two distinct machines used in brickmaking, — namely,
dry clay machines, using clay that has been dried by the sun and
wind, and wet clay machines, in which the clay is worked in its
moist condition as found in the bank. The stock from the dry
clay machines is produced by the employment of molds to shape
the clay. This product is more generally used for architectural
purposes. The wet clay machine stock is used for engineering
purposes, and is produced by forcing the plastic clay through a die
in a continuous string, which is afterwards cut into bricks of re-
quired size. Bricks made by the former class of machines are far
inferior as regards durability to bricks made by the latter machines.

PAVING BRICK AND BRICK PAVEMENTS. 93

I have read that some years ago in Washington, D. C, they had a
costly proof of this fact. The invert of a sewer in which the first-
named brick were used was entirely cut out by sand and gravel, and
let fall a section of more than 700 feet in length. To confirm this
statement I wrote to the Engineer Commissioner at Washington,
D. C, and Captain L. H. Beach, assistant in charge of sewers, writes
me that "our records show that the only case of sewer failure due
to defective invert occurred in 1877, when a section of the North
Capitol street sewer, about 245 feet in length, failed because brick
invert was washed out. The kind or quality of the brick was not
mentioned." However, what I have mentioned may be true in fact.

Analyses show that the best paving brick clays contain about
60 per cent, of silica, 20 per cent, alumina and the remaining 20
per cent, of iron, lime, magnesia, soda, potash and water. Alumina
gives elasticity to the brick, although an excess of alumina is liable
to produce checking or cracking in the kiln. The iron element
should be less than 6 per cent, when necessary to subject a brick to
high temperature. Lime is very injurious in a paving brick, and
should not be in excess of 3 per cent., as it is changed in burning
to caustic lime, which, when exposed to moisture, slacks, and conse-
quently disintegrates the bricks.

The difference between fire clay and shale brick is not clearly
defined. Generally speaking, fire clay bricks are of a light color,
varying from all shades of yellow to almost white, due to the
absence of iron and fluxing elements. They are capable of standing
a heat of 2000 to 4000 degrees Fahrenheit. Shale bricks vary in
color from a dark brown or red to a light gray, and possess more or
less of a tendency to a laminated structure. They also contain
about 8 per cent, of iron, which largely determines their color.
Fluxes to the amount of about 5 per cent, are also a characteristic
of the shale product.

In tests for compressive strength a great many shale brick are
found to stand about 5000 pounds more than fire clay brick. This
fact alone is not a material argument in their favor if it can be
proved that such excessive compressive strength is not necessary
for best efficiency, unless there exists correlatively a superior struc-
ture.

It would take too long to describe the process of manufacture
through its varying degrees of preparing the clay, grinding, screen-
ing, tempering, molding, repressing, drying and burning. Suffice
it to say that these several degrees in the process of manufacture
should be mastered in all their detailed operations by the workmen,
so that there would not be the slightest departure in their execution

94 ASSOCIATIOM OF ENGINEERING SOCIETIES.

day by day in order that a uniform product may be obtained. The
greatest defect in the paving brick industry of to-day is the lack
of uniformity in product from the same manufacturer. If manu-
facturers could be assured that all their brick could be made equal
to the best that they had produced they would be supremely happy,
not to speak of the joy that would come to engineers. Different
clays demand different treatment, and all demand the closest atten-
tion as to operation before and after setting in the kiln in order to
be assured of good results. I have recently heard of a new kind of
paving brick, composed of common coal ashes and a few chemicals,
which require no burning and are ready for use five hours after
made. Generally speaking, freedom of method in operation should
be accorded the several manufacturers, both for economy and effi-
ciency. The finished products alone should be required to meet
the standard of tests.

SIZE AND SHAPE.

Let us look at some of the finished products. They are of
varying sizes, shapes and color. Other things being equal, the
proper size and shape of paving brick should be determined
primarily by the element of commercial usefulness ; that is, they
should not be so small as to cause an unnecessary large number of
joints or to increase materially the time of laying them for pavement
or for any other purpose. They should not be so large as to afford
but little foothold for horses, although we may be approaching the
horseless age. However, when all phases of the question are con-
sidered, it seems to me that the proper size for a paving brick is
that of the ordinary building brick. Bricks of this size, when unfit
for pavers, can then be used for building and other commercial
purposes. This available secondary use, obtained by retaining
likewise the same shape as building brick, renders them cheaper for
each designed purpose.

Not a few brick advocates favor a brick with rounded top
edges; others lateral projections and grooves, or a combination of
both. However, nty experience has been that a brick with rounded
top edges presents a more attractive appearance in the pavement.
These several features, large size, shape, etc., may have some advan-
tages, but I do not think they are of sufficient importance to war-
rant their general adoption at the sacrifice of usefulness for other
purposes. It is claimed by some manufacturers that a brick of the
block form, on account of its large size, cannot be thoroughly and
uniformly burned. This claim, in point of fact, I do not think is
well grounded, although there is a limit of size. There is no impera-

PAVING BRICK AND BRICK PAVEMENTS. 95

tive demand for bonding brick together by special patented forms,
simply because there is no great strain to be distributed over the
impacted material that cannot be accommodated by the ordinary
form of brick.

CHECKS AND CRACKS.

There are some brick that are full of checks and cracks, par-
ticularly cobweb cracks. These have been caused probably in the
drying process, by drying too rapidly ; or they may have been hacked
in the wind or in a strong draft; or, again, they may contain too
much alumina, to which I have already alluded.

END CUT AND SIDE CUT BRICK.

Brick are cut the desired size in two ways, — namely, the end
cut and the side cut. The latter is more generally preferred,
because when laminations occur in brick, as is the tendency of in-
complete clay operations, they are found to be parallel with traffic,
and hence less liable to chip. This has always been the belief until
recently, when more complete tests by Professor Orton have
evidenced the contrary. See P. and M. Journal, March, 1897.

REPRESSING.

Many persons claim that a repressed brick is far superior to
what is known as the standard or square brick not repressed
because it is claimed that repressed brick are rendered more nearly
uniform in size and density and present a more attractive appear-
ance. But if by so doing the clay perchance be too dry, the bond
is broken and the structure changed ; then repressing is undesirable.
I am told by a manufacturer that repressed brick are harder to
burn, and when burned are apt to be hard on the outside and soft
in the center. Professor Orton's tests show that it is of great
advantage to repress end cut brick because of condensing lamina-
tions, and of great disadvantage to repress side cut brick. See
P. and M. Journal, March, 1897.

VITRIFIED BRICK.

The chemistry of burning, according to Chase, is at 100 degrees
C. the water held in mechanical suspension is driven off. That
held in chemical combination is driven off at a little below red heat.
At a red heat the carbonates are decomposed, and organic matter
is consumed. At a white heat vitri faction takes place, and from
here the kiln is gradually cooled. Professor Baker says : "Vitri-
fied brick are generally very hard, and generally also equally brittle
and unfit for a pavement. There may be clays which make the

96 ASSOCIATION OF ENGINEERING SOCIETIES.

best paving bricks when burned to vitrifaction, but the writer
(Professor Baker) does not remember having seen any such." On
the contrar}^, Mr. C. P. Chase, an engineer of Iowa, in speaking of
defective brick in a pavement one year old, says : "There were not
a large number, but sufficient to show that brick, no matter how
hard or compact they are, will not do for paving unless evenly
burned and vitrified." I have in mind one vitrified brick product
which I have tested, the results of which are in accordance with
Professor Baker's idea. It absorbed very little water, about one-
quarter of one per cent. ; was so very hard and brittle that it flaked
off in chips when in the rattler, rendering its abrasion percentage
very high. It had long been my impression that this brick was
burned too hard ; that is, too highly vitrified. Yet later tests show
it to be very satisfactory. In correspondence lately with the manu-
facturer of this brick I found that the mixing had been decidedly
more thorough, and that the time of burning had been reduced from
eleven days to nine days, which undoubtedly accounted for better
results. There may be clays that demand vitrifaction for best
efficiency, but this is not true of all clays.

SALT GLAZED BRICK.

Does salt glazing improve paving brick ? Many claim that it is
done to cover up structural defects. Salt glazing, however, can
only be applied to hard-burned material. If there be any great
injury done by its use it is that caused by the natural dampness of
the salt being imparted to the kiln when at a high temperature, thus
suddenly cooling the bricks, thereby having a tendency to check or
crack them. Salt glazed bricks would naturally absorb less water
than others. But this is no great advantage over other bricks if
their absorption is not excessive ; that is, above what has been
deemed reasonable, and is in harmony with other desirable qualities.
Salt glazed brick, presenting a glazed surface as they do, are more
slippery than others. Several manufacturers have informed me
that they did not believe in salt glazing paving brick. I have here-
with tabulated some information that may be of interest, sent me
at my request by several manufacturers of paving brick.

STANDARD TESTS.

Let us now examine the structure further by a standard of
tests. I do not think there is a more opportune time than this to
emphasize the necessity for a standard of tests that may be
uniformly adopted in every detailed operation, so that we may not
only know the comparative value of different paving brick, but also

PAYING BRICK AND BRICK PAVEMENTS. 97

the probable durability of the same under such and svich extent of
traffic with given modes of construction. Hundreds of tests of
paving brick have been made that are only of local value, because
of the varying conditions governing them. We note with pleasure
the progress in this line of the committee appointed by the National
Brick Association for the purpose of outlining a standard of tests
for paving brick, based on careful experiments. The tests that have
been adopted by those who have given the matter special study are :

1. Lime test.

2. Specific gravity test.

3. Transverse test.

4. Crushing test.

5. Absorption test.

6. Abrasion test.

In the annexed table will be found these several tests as con-
ducted by different authorities.

The necessity of tests to determine what kind of brick shall be
used is conceded by almost all. There seems to be the greatest
difference of opinion concerning the abrasion test. One writer
deprecates the use of Quincy granite as employed by another in the
abrasion test for comparison, because of the lack of uniform condi-
tions. This is quite right in point of principle ; namely, that no
comparison of results should be made unless governed absolutely
by the same conditions. Theories and arguments work out very
nicely when based on given conditions. But let us first be sure
that our conditions are given, are absolutely certain. For instance,
the complete identification of the brick throughout all the tests, the
correct weights, the use of similarly shaped scrap iron, or foundry
shot of certain number of pieces, and of certain weight, and the
same number of brick each time, the time and speed of running the
same rattler, — all of these requirements make up uniform given
conditions. These conditions of uniform tests can best be obtained
by the municipality possessing a testing laboratory of its own,
where materials and detailed operations of testing may be under
the immediate care of the engineer in charge.

Of late there has been a tendency on the part of some to discard
the absorption test, because it is claimed that any brick that will
stand the rattler test will stand the absorption test. I think that
the abandonment of this test would be an unwise procedure, for
every test has its value which is of no little importance.

In reference to the absorption test I have found that out of ten
different kinds of brick, there being two of each, in one set of ten

98

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the bricks were broken in halves, and in the other set the top, bot-
tom and narrow end faces were removed for about one-half inch;
that in this latter set the absorption percentage was higher in eight
out of ten bricks than in the former set. The absorption percent-
age upon similar whole bricks was less than either, showing that the
interior of the brick was more porous than the exterior, and also
indicating, since this was with forty-eight hours' immersion, that
twenty-four hours' immersion would have been too short a time for
this lot of bricks, and I think in general for all brick, although, of
course, the greater amount of absorption would occur in the first
few hours.

I do not think there is any definite dependency of abrasion on
absorption, save in maximum and minimum absorption there is
generally the greatest abrasion ; in the one case the bricks being too
porous and soft as to wear away gradually, and in the other case
being so hard as to flake ofif in considerable quantities. A study of
the annexed graphic table of tests in which Medina sandstone was
also tested for comparison will* prove the foregoing assertion. In
reference to abrasion, the difficulties encountered by the adoption
of a standard of tests when departing from what has been the
custom are at once apparent when one compares new results with
former results, for there has been much of indefiniteness in tests
everywhere. However, the way is to make the radical change if
necessary when a standard test has been developed, and then all
results may be justly compared. I do not think it advisable to use
cast iron bricks or pieces of pig iron in the tumbling barrel, princi-
pally because a use of them causes a severity of results unwarranted
and unfair when actual service in the pavement is considered.
Again, tests are not so comparative as we think when under such
conditions. Should abrasion percentages be compared one with
the other, even in the same tests, where large iron blocks or pieces
of pig iron are used when the chances exist of one brick being
unduly pounded more than its neighbor? To show the effect of
speed of revolution on results in practically the same sized and
shaped barrel under practically the same conditions, except that of
speed, the number of revolutions being practically the same, I have
arranged these tests, made as follows, upon the same kind of brick :

RATTLER, THREE FEET LONG BY TWO FEET DIAMETER.

Speed, 30 to 35 revo- Speed, 52 to 56 revo-
lutions per minute. lutions per minute.

• ABRASION, PER CENT. LOSS.

First Tumbling 13.88 per cent. 7.28 per cent.

Second Tumbling, alone 4.66 per cent. 2.26 percent.

Total of first and second Tumblings 18.00 per cent. 9 46 per cent.

lOo ASSOCIATION OF ENGINEERING SOCIETIES.

It will be observed that with nearly double the speed there was
only about half the loss, showing that with the higher speed the
barrel went so fast as to carry the bricks with it, and in consequence
there was less abrasion. Some one has suggested that the circum-
ference of the tumbling barrel should be composed of the brick to
be tested, laid close together, as in the pavement, and then sub-
jected to the abrasion wear of scrap iron, etc. This idea has con-
siderable merit in it, although it takes into consideration principally
the grinding effect, necessitating a large number of rattler revolu-
tions to get material results. In formulating standard tests it
should be borne in mind that the object of tests should be to find
the faults of a brick; that is, if it is porous, to what extent; or if it
be brittle, to what extent, etc. An immersion of forty-eight hours
is generally admitted to be sufficiently long to determine the
absorptive value of a brick. Abrasion tests, in accord with the
conclusions from experiments by Harrington and others, seem to
approach very nearly to what is desired for a standard of tests in
this line. I refer to these tests specially because most attention and
importance have been given them.

PAVEMENT FOUNDATIONS.

Having now examined paving brick, let us look for a few
minutes at the subject of pavements in general and their founda-
tions, confining the discussion more particularly to brick pavements.
There are a few primary elements essential to a good pavement, as
mentioned by General Gilmore :

1. That it shall be smooth and hard, in order to promote easy
draft.

2. That it shall give a firm and secure foothold, and not be-
come slippery from use.

3- That it shall be easily cleaned, and shall not absorb and
retain surface liquids, but discharge them quickly into the gutters
and catch basins.

4. That it shall be noiseless and as free from dust and mud as
possible.

5. That it should be readily taken up and repaired.

6. The roadway surface must be constructed of durable
material.

These well-recognized requirements should be borne in mind
when judging the efficiency of any pavement. The nature of pave-
ments and their foundations in different cities is largely determined
by the available material immediately adjacent to the localities, as
the transportation of foreign material from great distances is quite

PAVING BRICK AND BRICK PAVEMENTS. loi

a large item in the first cost, and more or less so consequently in
cost of maintenance.

CHOICE OF A PAVEMENT.

The choice of a pavement, after the above requirements have
been considered, is dependent upon local conditions of grade, cost,
etc., the popularity of home industries and, unfortunately, in some
cities upon the ascendency of one political party or another. The
relative rank of merit of different pavements, compiled from experi-
ments and facts of actual service, is shown in the annexed tables.

It will be observed that brick stands in the front ranks, and
surpasses asphalt in a majority of the requirements.

There are now about 200 miles of asphalt pavement alone in
Buffalo, which amount represents about $10,000,000. Estimating
brick at 30 cents a square yard less than asphalt, if it had been
chosen by the people its use would have saved $1,000,000 in first
cost, which at 5 per cent, interest represents $50,000 per annum.
Supposing the cost of maintenance and durability the same, the
question is, are the blessings of asphalt pavements so far superior
to those of brick pavements to the amount of $50,000 every year?
This suggestion, however, must be modified to this extent,^namely,
that indefiniteness as to the efficiency of paving brick has in the
past precluded its use. This indefiniteness is not so pronounced
to-day as formerly, when the efficiency of asphalt was also ques-
tioned.

In New York City there is no great amount of brick pave-
ment, and I find these remarks in the Paving and Municipal Engi-
neering Journal for October, 1895: 'Tn New York they have ten
or more streets paved with asphalt where the grade varies from 2.5
to 6 per cent. One of these streets, with a 6 per cent, grade, was
used in preference to parallel streets of less grades that were paved
with blocks. Also traffic has deserted Ninety-third street, paved
w^ith granite, for an asphaltic pavement with a 6 per cent, grade in
Ninety-fourth street. The granite pavement of Fifth avenue,
between Thirty-fourth and Thirty-sixth streets, with 4.87 per cent,
grade, has to be sanded for safety." In Syracuse I find James
street has a grade of 7.3 per cent., and in Rochester Spring street
has a grade of 5 per cent, and Clifton street 4.5 per cent. An
investigating committee when visiting these cities was informed
there was no difficulty in driving over the above-mentioned streets.
In Buffalo I think the steepest asphalt grade is one of 5.10 per
cent, on Utica street, from Main street easterly. Delaware avenue,
from Forest avenue to the creek, has a grade of 4.40 per cent.
Church street, from Pearl to Franklin, has a grade of 3. 11 per cent.

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Delaware avenue, from North street southerly, has a grade of 2.83
per cent. In Buffalo we have endeavored to avoid as far as possi-
ble making' grades of asphalt pavements greater than 3 per cent.
Some asphalt pavements of 4 to 7 per cent, grades may not be
difficult to travel over if the weather is warm and high temperature
has softened the asphalt so as to afford a foothold for horses, but in
winter and with rainy, freezing weather I have seen drivers forsake
an asphalt of 0.4 per cent, grade for a stone pavement. A brick
pavement, because it will not wear smooth or polish, -as do some
stone pavements, will permit the use of any grade that may be
desired.

UNDERGROUND IMPROVEMENTS.

The first consideration for a good pavement is the question of
assurance that all main sewer, water, gas and other pipes or con-
duits and lateral house connections are in good condition as regards
quality and trench settlement. Too much attention cannot be given
to these underground improvements. The second important step
is that all pavements, of whatever nature, should be laid in good
weather and under all other favorable conditions as may be
obtained. The street should be graded two feet wider than width
of paving to proper grades, and sub-grades conformable to pro-
posed crown of finished pavement. Soft or spongy places, not
affording a firm foundation, should be dug out and refilled with
good earth, broken stone or other equally good material, well
rammed. The sub-grade should be thoroughly rolled with steam
roller not less than five tons weight. No ploughing for rough
grading should be done within 3 inches of the sub-grade.

DRAIN TILE.

Unless a sandy or gravel material exists, as the street grading
progresses, a 4-inch porous drain tile, with open joints, to be
covered with broken stone, should be laid on each side of the street
back of the curb, in straight line and true grade, about 24 to 30
inches from top of curb to top of tile, so that water may be pre-
vented from reaching the foundation of pavement. If the street
has a heavy descending grade, then the use of drain tile is unneces-
sary. I find that a great many cities do not use drain tile, but we
find in Buffalo that its use is of great advantage to the life of a
pavement.

CURB.

The curb, which should be good, hard stone not less than 4
inches wide and 18 inches deep (preferably 6 inches wide and 12

PAVING BRICK AND BRICK PAVEMENTS. lOS

inches deep), and not less than 36 inches long, dressed evenly,
should be set in concrete or sand, backed by 6 to 8 inches of same
material, care being exercised to set it in true line and grade. At
the end of each curb, when set in sand, should be placed a small
stone at the base, to prevent curb from being forced out of line.
Upon the finished sub-grade shall be placed the foundation course
of prescribed material. An examination of the table of comparative
construction and cost and efficiency of brick pavements in various
cities, — fifty-five in number, — which I have compiled from informa-
tion sent me by several city engineers, will reveal the customs
employed for a foundation course, as well as many other items of
interest in pavement construction.

FOUNDATION COURSE.

Some use sand, others gravel ; others furnace slag, others an
under course of brick laid flat ; others broken stone, and others con-
crete of varying thickness, dependent upon traffic. A concrete base
has been generally recognized as the only permanent base. Its use
may be quite desirable and altogether wise in the case of wet,
spongy land that requires a well-bonded bed over which may be
distributed heavy loads that may come upon it, to relieve the
immediate local effect; but for sandy gravel soils and those of stiff
clay, and where traffic is not extremely heavy, a concrete base does
not appeal as the most economic and efficient one. There is quite
a difference in broken stone, say at $1.30 a cubic yard, and concrete
at S3. 50 a cubic yard. Some of the best pavements in Buffalo have
a 6-inch to 8-inch broken stone base. Again, concrete is not
entirely stable, for its movements have caused much disturbance
and no little expense to restore to the rightful place where the
upheavals and cracks in asphalt and brick pavements particularly
have been experienced.

From experiments in England by Geo. R. Strachan, A. M. Inst.
C. E., in which a strip of concrete 6 to i ballast, 52 feet long, 12
inches wide and 3 inches thick was laid on sand to allow freedom
of movement under a shed with open front, so situated that the sun
did not touch it, and another strip 26 feet long, same width and
thickness, 3 to i pebbles, and a third of the same dimensions, 3 to
I sand, were also laid under the same conditions. The only move-
ments that he discerned at the end of the month was a slight con-
traction in length in all the samples. He further says "that the
uniform experience of concrete under asphalt is that cracks occur
which would tend to show that contraction, not expansion, was the
rule." These cracks in asphalt are not wholly due to the concrete

io6 ASSOCIATION OF ENGINEERING SOCIETIES. '

movement, as here in Bufifalo, where some experimenting with
asphah has been done, cracks are so numerous that it would be
absurd to ascribe the cause to movement of the concrete, the nature
of the asphalt and its manipulations being responsible for such
effects. Where the expansion of concrete has been experienced
it has been attributed to the action of temperature. Curbing that
has on one side asphaltic sidewalk and on the other asphalt roadway
has been forced out of line toward the center of the street by the
expansion of the concrete pushing respectively the top one way and
the bottom of the curb the other. In our city of Buffalo we have
had no little experience with concrete raising up asphalt pavements,
particularly as though a root of a tree had grown underneath.

These effects have not been more generally experienced because
mastic asphalt, being elastic, and binder coating, when used, have
regulated more or less the movements of the concrete. Although
Mr. Malo, the French authority on asphalt pavements, states that
the cracking of asphalt pavements is largely due to the use of oils
in fluxing and softening the mixtures, and deprecates the use of
petroleum or other similar oils for such purposes, many engineers
believe that it is due to the laying of asphalt pavements late in the
fall and subject to variable weather, and, second, to not removing
all moisture from the concrete before the asphalt is laid.

The expansion of concrete, I think, as well as the expansion of
brick and the cement filling, has been to some degree the cause of
the complaint that has come from cities in reference to the rumbling
noise and cracking of brick pavements. The concrete course, as
well as the brick course, has arched or shoved up, leaving hollow-
spaces that cause the rvmibling noise, intensified, of course, by the
very nature of brick itself.

CUSHION COURSE.

On top of the foundation course for brick pavements a sand
cushion is generally placed. In different cities this ranges from
l inch to 2 inches in thickness. Where the top surface of the con-
crete is left rather rough I think a 2-inch cushion should be
employed to take up in some degree the movements of the concrete
and to offset inequalities of brick. In reference to the efficiency of
a .sand cushion, it certainly is not perfect, especially with a broken
stone base, as in some cases it has worked down between the pieces
of stone ; and because of this one writer deprecates the use of a
broken stone base. A desirable cushion would be one of an elastic
nature. Sand does not meet this requirement, and yet it seems to
be the only practicable cushion.

PAVING BRICK AND BRICK PAVEMENTS. 107

SELECTION OF BRICK BY COLOR.

For the selection of brick to be used in the pavement there
seems to be no definite guide. Tlie kind of fuel used in burning
will affect the color, not to speak of the constituent elements of the
brick itself. I have made tests of brick where the varying colors
of the same product were particularly noted, and no special differ-
ence in absorption and abrasion was observed except in extremes.
Very dark-colored brick are generally overburned, and, being too
hard, are liable to chip off in fragments, while pale, very light-
colored brick, being underburned, are not as tough as others.
These conclusions are operative upon different-colored brick of the
same product, and not upon different products. Generally speak-
ing, the medium-colored brick of any product are the toughest and
most durable. Again, that kind of brick is best for paving pur-
poses which when broken reveals a close, homogeneous structure of
uniform color, the break being a clean, sharp one.

After the selected brick have been laid with proper crown
(which should be parallel with the crown of foundation course and
roadbed), and at right angles to the curbs, breaking joints evenly,
they should be rolled with a steam roller and all cracked or broken
brick replaced by good, whole brick. In reference to the crown of
a brick or stone pavement, it is advantageous that it should be
lower than the curb grade, so that in the future, after the brick
pavement has served its time, it could be surfaced with asphalt if
competition with brick pavements should so lower the price of that
material that its use would be cheaper than to supply new brick
where needed.

FILLING OF JOINTS.

The question of filling joints now presents itself. Some cities
have experienced no little trouble in the use particularly of neat
cement, and also of a composition for joints. Sand filling is
employed in some cities, but the liability of water percolating
through the joints and causing trouble has undoubtedly limited its
use. However, there has been no special complaint from cities
where it has been used that can be traced definitely to this cause.
Coal-tar pitch and asphaltum pitch have been used also for filling of
joints. The joints of brick pavements laid in Buffalo in 1892 were
filled with pitch ; but this was abandoned in 1893, cement grout
being used since then. The pitch under high temperature softened,
and consequently was more or less of a nuisance to passing vehicles.

In Newark, X. J., fire-clay brick were laid in December, 1895,
at a temperature below freezing point, cement grout being used

io8 ASSOCIATION OF ENGINEERING SOCIETIES.

with salt to fill joints. The brick raised, due to supposed expansion
of the brick, and resulted in more or less rumbling noise when
vehicles passed over. At the same place a brick pavement laid in
warm weather, the joints being filled with Portland cement, the
rumbling noise has also been experienced, but not to such a large
extent as that from pavement laid in cold weather. The Newark
authorities are thinking of abandoning the use of cement filling for
pitch mastic. Experiments are now in progress there with a combi-
nation of both; that is, spaces for 15 feet at intervals across the
full width of pavement and for one inch along the curb being filled
with a paving mastic, the remaining space being filled with cement
grout in the hopes of counteracting the expansive power of the
cement.

In Cortland, N. Y., where pitch and cement were both
employed, the cement in setting within three days forced the pitch
out of the joints. This cement had been tested previously for
expansion. After the cement had set the expansion seemed to
cease.

In Brooklyn, N. Y., on the McDonough street pavement, where
they were troubled by a rumbling noise, the bricks having arched
up, a 15-ton steam roller was used in the hopes of breaking the
joints. Then a brick or two along the curb was taken out, but even
this was of no avail. The theory is that when work was in progress
the temperature fell 10 to 15 degrees and froze the sand and con-
crete. I think that it has now about been decided to remove the
brick, so great has been the complaint against its rumbling noise,
and lay asphalt on the concrete foundation. This step, if it be
taken, will be greeted with joy by asphalt advocates. The above
theory, however, as to the cause of such disturbance is contradicted
by the experiences in Newark, N. J., to which I have alluded.

On South Sixth street, Terre Haute, Ind., a pavement of Can-
ton brick laid about five years ago gave trouble by rising up in
several places. Its construction extended into the winter, and was
completed early the following spring. The brick were laid close on
broken stone foundation on 2-inch cushion of sand, the joints being
filled with Murphy grout.

In Easton, Pa., on account of an 8 per cent, grade, the joints
near the gutter of a brick pavement were filled with cement grout
for a width of (2 feet in report of city engineer of Easton) 4 feet
from the curb, the remaining part being a sand filling. This
resulted in a ridge of one-half to three-fourths of an inch in height
along the division line between the cement grout joints and the sand
joints.

PAVING BRICK AND BRICK PAVEMENTS. 109

In Wilmington, Del., where they were troubled with a rum-
bling noise, a strip in the center, 100 feet long and 18 inches wide,
was removed, but this afforded no relief.

In Buft'alo we have not been troubled seriously by any such bad
effects. Dart street, paved in October, 1892, with pitch filling in
joints, the brick laid close on concrete base, has one place where
there is a rise of about 4 inches for three-fourths of the width of
pavement. This is probably due to concrete expansion. Also in
1892 Oakdale place, with cement joints, laid by private parties, has
bulged up in three or four places to a very small extent. The
general condition of the street is good, although I understand a
common cement was used for filling joints.

Penfield street, paved in May, 1893, cement joints, has some
longitudinal cracks, due in this case probably to water getting under
pavement from frozen water pipes, as well as to cement expansion.

Roos alley, paved in October, 1894, has some brick cracked
longitudinally in a few places and depressed where repaired below
general surface, caused probably by gutter in the center and cement
expansion and concrete movement, and also trench settlement.

Laurel street, paved in 1895 and 1896, cement joints, laid by
private parties, has some small longitudinal cracks, probably due to
cement expansion.

Ada place, paved by private parties in the fall of 1894 and
spring of 1895 with an American Portland cement composition, in
the proportion of one of cement to six of gravel, has now about
eighteen cross cracks and two or three longitudinal cracks. These,
however, are no discredit, to this particular cement, for I believe it
to be of high quality, and I understand its expansive power is very
slight. A defective sub-soil, together with whatever little expan-
sive power the cement might possess when provoked by the
elements, would be responsible for the above effects.

The annexed table of brick pavements in Buffalo gives special
information concerning length, yardage, cost, etc.

From the foregoing instances we have seen that trouble has
been experienced from brick pavements of fire-clay and also shale
structure, not only on a concrete base, but also on a broken stone
base, and where neat cement and also cement grout and pitch have
been used for the filling of joints. Brick pavements laid in warm
weather have given forth a rumbling noise, although not to such a
great extent as those laid in cold weather. Cement grout, where
used in Buffalo, as in most other cities, has been proportioned i to i,
and as used thusly one barrel of English or German Portland
cement covers about 40 to 50 square yards, at an average cost of 13

no ASSOCIATION OF ENGINEERING SOCIETIES.

cents a square yard for sand, cement and labor, the amount covered
depending- largely on the size of brick used. The expansive power
of cement when used should be little or none, as therein is the dis-
advantage of its use. Coal tar and asphalt tillers have the disadvan-
tage of softening up in warm weather and running off from the
brick, particularly from the center to the gutters, leaving the edges
of the brick exposed to immediate abrasion. Sand as a filler, as
well as paving mastic, are considered detrimental to the life of a
brick pavement because also of exposing the edges of the brick.

The combination of cement grout and paving mastic has not
been sufficiently long in use to judge of its efficiency. What is
known as Murphy's grout has been used for filling joints in some
cities with considerable success, at an average cost of i6 cents a
square yard. It is chiefly composed of iron slag and carbonate of
lime, clean, sharp sand being added in proper proportion when used
on the street. This grout is very hard, and consequently protects
the edges of the brick ; but does not accommodate itself, as far as I
can learn, any better than other fillings to brick and cement concrete
expansion. When a filling is harder than the brick the expansive
power of the brick and cement tends to crack and upheave the brick.
When a filling is softer it wears away, leaving the edges of the
brick exposed to wear. What is needed is a hard, elastic filling that
will accommodate itself to brick and cement expansion and concrete
movement, and which will not soften materially under increasing
temperature.

DURABILITY OF BRICK PAVEMENTS.

As to the durability of brick pavements one engineer put their
life at ten years ; another said in 1891 that many were in good con-
dition that had been down fifteen years, and several over eighteen
years old were giving satisfaction.

Prof. Ira O. Baker, in his pamphlet on brick pavements, gives
considerable information, based on experiments, as to their dura-
bility. In Buffalo, for instance, on Main street, near Swan street,
pavement width 56, he estimates that with a total daily tonnage of
2613, or 0.83 ton per vehicle, making a tonnage of 47 per foot of
width, that 100 per cent, of sample brick No. 6, the best in the test,
would wear away in 226 years, and sample No. 10 in 25 years.

And in New York City, on Broadway, near Pine, pavement
width 40 feet, with a total tonnage of 10,905, being 1.39 per vehicle,
making 273 tons per foot of width, sample No. 6 would lose 100
per cent, in thirty-eight years and sample No. 10 in four years. Of
course, this durability considers the effect of traffic only, which,

PAVING BRICK AND BRICK PAVEMENTS. in

however, is the most important item. Again, a pavement would
not be of practical use during this period of lOO per cent, wear
unless all brick could be worn down ecjually at the same time, which
would be impossible. Experien»e has proved that a brick pavement
shows more wear due to the abrasion of the edges in the first year
than it does in the next six years. From my own tests of abrasion
as indicative of durability, I have found the best paving brick equal
to ordinary Medina sandstone. The best brick in the tests by
Professor Baker was found equal to Quincy granite.

So far I have endeavored to present a fair, impartial and just
consideration of the question of paving brick and the construction
of brick pavements as now in progress in various cities. I have
avoided as far as possible laying stress upon any particular merit
or merits that a brick pavement may possess.

But let us look for a few minutes at some of the advantages
claimed for brick pavements. They have been tersely enumerated
by W. P. Judson, C. E., as follows :

1. Less first cost than sheet asphalt, which is its only
competitor.

2. Less ultimate cost, as few repairs are needed if good brick
are used.

3. Ease of construction and repair.

4. Ease of traction and of cleaning, and freedom from dust
and mud.

In reference to the first advantage stated, it is conceded by
nearly all that brick and asphalt are the great rival pavements. The
less first cost is conceded by asphalt advocates.

In regard to the second advantage, less ultimate cost, it is
claimed by asphalt advocates that owing to the short life of brick,
its brittle and friable nature when subjected to traffic, makes it
more expensive ultimately. Some paving brick that have been
manufactured have undoubtedly warranted this conclusion, but
such brick are far from representative of the character of paving
brick in general.

The third advantage of brick — namely, ease of construction
and repair — is self-evident, although it must be admitted that
asphalt is now repaired by the aid of modern improvements with
considerable more ease than formerly.

For ease of traction on the general run of grades asphalt is
superior, as well as in cost of traction. I beg to differ with Mr.
Judson also in regard to the ease of cleaning, although in street
cleaning contracts brick is classed with asphalt. Again, for better
freedom from dust and mud, asphalt ranks foremost. But this is

112 ASSOCIATION OF ENGINEERING SOCIETIES.

not a decided advantage, for there is just so much dust and mud
from adjoining unpaved streets, etc., which must be distributed
somewheres, and, if not upon the asphalt pavement, the dust is
blown into abutting houses. Whereas with brick pavements, if the
joints are a defective element in them, then these joints would
receive the dust and dirt, which ought to be frequently and regularly
collected by the street cleaning department.

In point of noiselessness, which Mr. Judson does not mention,
some brick pavements as have been constructed are far inferior, and
in general they produce more noise than asphalt. I will also add
that brick is not materially affected by moisture or fire, as is asphalt,
and therefore brick is superior in these respects.

In conclusion, it is not wise, nor is it just, to determine the
efficiency of any pavement by casual impressions, such as comfort
of riding, pleasing appearance, etc., for there are many considera-
tions, as we have seen, besides these items already mentioned that
should determine the efficiency of a pavement.

If I have prompted you to think with favor of paving brick,
from the clay bed through their development of manufacture to a
material of engineering usefulness in affording a cheap and durable
pavement, when properly laid, for hundreds of cities that through
their use only can enjoy the blessings which come from well-paved
streets, I shall have accomplished a great deal in writing this paper.

DISCUSSION.

Mr. Ricker. — I would like to ask Mr. March if he is familiar
with the brick pavement on the principal street connecting Dunkirk
with Fredonia?

Mr. March. — I have information from Dunkirk in the list of
cities in reference to foundation course, etc.

Mr. Ricker. — I have had very little experience with pave-
ments, but this is a particularly disagreeable and noisy pavement ;
riding over it is exceedingly disagreeable on account of the noise.

Mr. March. — That seems to be the great trouble in a brick
pavement. It is so sensitive when riding over it that vehicles pro-
duce a rumbling noise.

Mr. Mann. — I can answer in part. In some of the streets in
Dunkirk they laid water and gas pipes and sewer lines just prior to
laying the pavement, and undoubtedly the earth has settled away
under the concrete, consequently we hear the rumbling noise along
the line of the trenches ; the concrete holds the pavement up, and it
is hollow underneath. There were transverse cracks across the
street. What caused this transverse cracking nobody knew.

Mr. Guthrie. — In Chicago there was a discussion on this

PAVING BRICK AND BRICK PAVEMENTS. 113

point with reference to Brooklyn, Newark and Syracuse also.
Some of this rumbling sound is caused by hollow places, the earth
settled away and the sand cushion being washed away through ex-
pansion of the concrete.

Mr. March touched upon the question of the uniformity of
brickmaking ; I do not believe we have uniform brickmakers. It is
necessary to see that they are more uniform in their making of brick
for paving, as I think if the same method of making is used by all
makers good results may be reached and certain benefits got by
standardizing the tests.

As to the disagreeableness of riding over brick pavements, it
seems to me so many joints cannot but make riding in light buggies
disagreeable in consequence of striking so many joints.

Mr. Green. — What material has been selected so far as a
standard for hardness ?

Mr. March. — Professor Wheeler has a formula in which he
uses H. for hardness in the mineralogist's scale, brick value 6-^.

Mr. Green. — What material is used as a standard, as I under-
stand the paving brick is tested by a grinding machine which is
simply an emery wheel, taking a brick of some standard material
and grinding the brick for hardness ?

Mr. A-Iarch. — Granite. An engineer of Peoria, in contradict-
ing Professor Baker relative to the use of Quincy granite, said he
had some granite he had tried to have cut down to a regular-sized
dimensioned cube, but he found it was almost impossible to get it
:ut down to the required size and shape. However, Professor
Baker uses Quincy granite for comparison, because, granite pave-
ment being the hardest known pavement, any brick that would
be equal to that in comparison is suitable for pavement.

Mr. Green. — Granite varies so much in composition and
amount and size of the materials which compose it, and in the
amount of quartz and other material. Though granite is used in
pavements, it would not be used for a comparison for cements.

Mr. March. — Here in Buffalo we do not use granite, but
Medina sandstone, cut down to the same size as the brick, is put in
the same barrel with the brick. Our desire is to get a comparison
between the brick and sandstone.

Mr. Green. — That brings up the same question, which sand-
stone ?

Mr. March. — Gray and red mixed. Gray sandstone is the
hardest ; it has proved to be in tests.

Mr. Green. — One standard of materials for hardness is quartz,
but granite is a conglomerate of very different substances, and I do
not see how that can be used as a base or standard.

114 ASSOCIATION OF ENGINEERING SOCIETIES.

Mr. Ricker. — Do you have very much trouble with pavements
on account of the foundation ?

Mr. Mann. — Bad underground work will ruin any pavement.

Mr. March. — This has been found to have been the ruin of
parts of pavements.

Mr. Ricker. — I remember when I was a boy in England that
when paving one street they must have gone down five or six feet
for the foundation for a block pavement of some stone similar to
Ouincy granite.

Mr. March. — In laying some pavements we have gone down
four or five feet.

Mr. Norton. — I have seen some places where it was necessary
to go that depth. The future importance of paving brick is a
question resting both with the engineer and with the manufacturer.
It would be well to have some uniform standard and uniformity of
test which the makers may be prepared to meet ; after the engineer
has done that, his scope is over. Investigation necessarily must be
founded on a standard. This we have found in brick pavements
within the last few years.

Niagara Falls has had trouble, as I understand it, not so much
in the rumbling and upheaval as in the character of the base and
filling for the pavements. I do not see how it is possible to use a
broken stone base with a sand cushion without losing all of the sand
between the broken stone ; the sand will be washed into the spaces
between the broken stone used in the foundation, leaving the sur-
face in very bad shape. It is necessary, however, to level up the
foundation to get a uniform base upon which to lay the brick.
From my own experience I do not think it possible to roll unequal
brick to a true surface on either a i or 2-inch cushion. They
must be sorted or sized in laying. On a street on which we were
using a i-inch cushion of sand this season there came on a heavy
rain, and the water ran down from the center to the gutters and
washed the sand away, and the brick had to be relaid.

Mr. Mann. — Because of the broken stone base?

Mr. Norton. — No. It was on a concrete base.

Mr. Ricker. — The sand was washed crosswise into the gut-
ters?

Mr. Norton. — It was washed from the center to the side,
through the joints, which necessitated taking up the pavement.
Small depressions showed along the center of the street after it was
cemented ; when taken out the sand was found to have been washed
out by the rain. It does not seem possible to use sand with broken
stone wathcut losing all of the sand filling. In the matter of the

PAVING BRICK AND BRICK PAVEMENTS. 115

rumbling noise, it has been general in the West. There are cases
where the pavement, laid in cold weather and afterward cemented at
a low temperature, has expanded a certain amount, probably due to
the expansion of the brick and cement. If the brick were laid in
very warm weather and thoroughly wet in cementing, they would be
cooled down to the temperature of the water with which they were
flushed, and the brick and cement would afterward expand from
the temperature of the water to that of the air. Pavements may
be laid in a temperature of 80 or 90 degrees, but the brick would
be at a temperature considerably below 50. Raising the tempera-
ture above 100 would be sufficient to account for considerable
expansion.

Mr. March.- — If a broken stone base is used I think it is impor-
tant that some filling other than cement should be used. In refer-
ence to the 2-inch sand cushion, in Buffalo, where it is customary to
lay concrete for asphalt topping, the top has been left rough in
order to get a better bond for the topping, and this has expanded
so much it is necessary to leave a joint in the concrete when laying
the pavement, and in that case, where the top of the concrete is
rough, the cushion could be increased ; that is, a thicker cushion
would be advisable in order to compensate for the inequalities of
the concrete and brick. If the sand is pushed aside the brick would
rest on the stone, so, in case of a rough top, it strikes me a 2-inch
cushion would be advisable; if the surface is smooth it is not so
necessary, and possibly a i-inch cushion would do.

Mr. Ricker. — There is a special claim made for brick made of
certain chemicals. Do you know anything about this ?

Mr. AIarch. — I saw reference made to them in some magazine
within the last week. They are composed of coal ashes and chemi-
cals, and requii-e no burning. They are ready for use in five hours
after being made.

AIr. Mann. — Put in the presses and molded?

Mr. March. — I suppose so.

Mr. Green. — Slag brick are used in Toronto. Simply for a
toothing along car tracks, laid in 2-inch sections.

Mr. Xorton. — Another point to be considered is in the laying
of the brick across the street and making the joints tight. If too
tight, in rolling it will make an arch across the street, and no kind
of filling will prevent that trouble.

Mr. Mann. — If brick and stone of the same size are laid on
the same bed, the brick will produce more noise than the stone
because of its metallic ring. Is this not so?

Mr. March. — Yes. Every pavement has its defects just as

ii6 ASSOCIATION OF ENGINEERING SOCIETIES.

anything else. The question is, Avhich has the least at the least ex-
pense?

Mr. Ricklr. — In case of brick between the rails of car tracks,
do you know whether the expansion is sufficiently distributed to the
gauge ?

Mr. March. — I do not know.

Mr. Ricker. — What I had in mind is, it is sometimes necessary
to pave between the tracks and outside of the rails, leaving parts of
the street unpaved. What would be the effect ?

Mr. March. — The effect of expansion. Expansion makes the
brick rise.

Mr. Ricker. — Another trouble would be, a roll forms on both
sides where there are hollow spaces under the girder rails.

Mr. Mann. — There is only a little space where the rails are
bolted together.

Mr. Ricker. — Of course they have to have room for the joints.

Mr. March. — I do not think it would be a serious defect.

Mr. Norton. — The trouble has been that the pavement ex-
panded over long blocks of the pavement rather than in the narrow
gutter.

]Mr. March. — It seems, however, to occur only in a very
small area, about three feet square, as on Oakdale place. Alost of
the trouble of any amount is in a small area.

Mr. Ricker. — Are the brick laid closer at the ends than at the
sides?

Mr. March. — The sides are not supposed to lay as closely as
on the ends. If any filling is placed between them it is liable to
cause transverse cracking across the street ; any expansion, of
course, would be noticeable there. On McDonough street, Brook-
lyn, the brick arched up that way, I believe, and though an attempt
was made to roll it down with a 15-ton roller it was without eft'ect.
They took out a line of brick along the curb, but it had no eft"ect.
It was a regular brick arch.

Mr. Mann. — If the cracks are shown transversely across the
street, then the expansion is transverse.

Mr. March. — That is probably true. It probably has no de-
fects at all on its surface, caused by the ends of the brick being laid
closer than the sides.

Mr. Norton.- — It is the tendency of the men laying the brick
to lay them in this manner. Probably the filling between the brick
has driven them up. Closing the joints at the ends with broken
brick makes the joint across the street very much closer.

!Mr. March. — Care oueht to be exercised in the selection of the

H.J. MARCH-PAVING BRICK AND BRICK PAVEMENTS.

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H. J. MARCH-PAVING BRICK AND BRICK PAVEMENTS

J

PAMXG BRICK AND BRICK PAVEMENTS. 117

cement for joint filling and foundation. In the Franklin street
pavement we used Royal Crown Belgium Cement in front of the
City Hall. The brick of the Franklin street pavement has been
generally good. There are one or two places that are bad.

;Mr. Xortox. — It shows a rumbHng in one or two places.

Mr. Mann. — Maybe Mr. Vander Hoeck can tell us something
about the pavements in Holland ?

^Ir. A^ander Hoeck. — There are several miles of highways
paved with brick in Holland. I am sorry to say they are in very
bad condition. They were laid years and years ago. There was
no attempt made to get a good foundation, and the bricks were
simply laid in sand ; consecjuently the pavement is full of holes, and
very expensive to keep up.

^Ir. \"ander Hoeck. — I do not know exactly where the trouble
is, but I thinks it is in the fomidation ; and in some places the mud
will come out between the brick. As far as the brick is concerned,
I do not think it will be very easy for the makers to make brick
conforming to a certain standard to last 200 or 300 years.

Mr.^Mann. — I went into an old mission in AhualuUo, Mexico.
In front of the altar were the distinct marks of the knees and toes
of the worshipers worn out in the brick. In the doorway it was
worn down to not more than one inch in depth. The brick were set
on edge. Thev were resfular sun-dried brick.

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

Association

OF

Engineering Societies.

Organized 1881.^ " "^

|u. NOV 2 im

Vol. XXm. SEPTEMBER, 1899. ^.4 v^ No._^

This Association is not responsible for the subject-matter contributed by any Society or
for the statements or opinions of members of the Societies.

COVERED RESERVOIRS.

By Frank L. Fxh-ler, Member Boston Society of Civil Engineers.

[Read before the Society, May 17, 1859.*]
FRANKLIN, N. H., RESERVOIR.

In 1889 the writer designed a covered masonry reservoir in
connection with a system of water supply for the town of Winchen-
don, Mass. The system was not built at that time, but the same
reservoir design was used in 1891 in connection with a water works
system for the town of Franklin, N. H.

A section of that reservoir and also a cut from a photograph are
given. The brick piers supporting the roof are 12 x 12 inches, laid
in Portland cement. The roof is of hard bricks laid in Rosendale
cement and 8 inches in thickness.

The average load at the base of each pier is a little less than
23 tons per square foot.

As the Winchendon reservoir is similar in construction, the
detailed description of that reservoir given further on, will answer
for' this, and also largely for the Methuen reservoir.

The Franklin reservoir was the second covered reservoir built
in New England, and the first circular one.

A copy of the final estimate for its construction, which was by
contract, will give its cost in detail:

* Manuscript received August 30, 1899.— Secretary, Ass'n of Eng. Socs.
9

120

ASSOCIATION OF ENGINEERING SOCIETIES.

2882.4

714.8

i8.6

120.8

57-5
410.8

464.4

52.S

73-9

Extra

COVERED RESERVOIRS. 121

cubic yards earth excavation @ $0.40 $1,152.96

" " local rubble masonry in Am. cement.® 6.80 4,860.64

" " Portland cement brickwork @ 16.96 315-46

" " American " " @ 13.96 1,686.37

" " " " concrete @ 6.75 388.12

square " i-inch Portland finishing coat on

bottom @ 45 184.68

" " J/2-in. Portland plaster coat on sides.. (gj .40 185.76

lineal feet 12-inch cast iron pipe laying (S< .50 26.25

" 6 " " " " " @ .35 25.87

for 40 barrels Portland cement on bottom @ 1.80 72.00

" 2 " " " used around pipes

and gates @ 3.48 6.80

not included above 127.45

5,032.36

METHUEN RESERVOIR.

In 1893 3- covered masonry reservoir of a capacity of 1,013,000
gallons was built by the town of Methuen from plans by the writer.
It is similar in design to the Franklin reservoir, but has an inside
diameter of 95 feet at the top and 93 at the bottom. The piers are

'7777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777771

Section of Outer Ring of Piers and Supporting Arches

The Inner Ring of Piers is the same except that the piers are 2 inches

Ion

F.— F.

ger.

also larger and the reservoir deeper. It is practically an enlarge-
ment of the Franklin reservoir by the addition of another circular
covering arch of the same span and rise.

The roof is supported by 60 brick piers 16 inches square, laid
in Portland cement.

The dome and covering arches are of brick, 8 inches in thick-
ness, laid in Rosendale cement. The average load per square foot
at the base of each pier is about 14. i tons. This includes a possible
load of 50 pounds per square foot for snow and ice in the winter.

122 ASSOCIATION OF ENGINEERING SOCIETIES.

The earth covering over the roof has a slope of about i in 38.
The embankment about the masonry wall where it is above the
original surface of the ground has a slope of i in 2.

The height of the middle row of piers from the bottom of the
reservoir to the springing hne of the lintel arches is 18.25 feet.
The piers are 7.54 feet apart on centers, measured along the cir-
cumferences of their respective circles.

When full, there is a depth of 19.7 feet of water in the reser-
voir.

All materials were furnished by the town of Methuen, and
delivered at the reservoir site. All work was done by day labor,
except in laying the rubble masonry wall. This was furnished by
Mr. Wm. S. Marsh, of Lawrence, at $1.64 per cubic yard. The wall
contained 1084 cubic yards. Mr. Marsh also put the plaster coat on

the inside of the masonry wall for the sum of 23 cents per square
yard. This coat was composed of equal parts of Portland cement
and sand.

The total cost of the reservoir, exclusive of land, was $16,-
864.64.

HARVARD RESERVOIR.

In 1895 the writer made plans from which was built a small
covered reservoir for use in connection with the water supply for
the residence of Fiske Warren, Esq., at Harvard, Mass.

The reservoir is 22 feet in diameter at both top and bottom, and
13.5 deep. The walls are of local rubble stone, partly obtained at
the reservoir site. The reservoir contains, when at high water
level, 12 feet of water, or 34,100 gallons.

COVERED RESERVOIRS. 123

The roof is a circular dome 22 feet span and 3.5 feet rise. It
is composed of brick laid in American cement, and is 8 inches in
thickness.

The bottom consists of 6 inches of concrete.

The writer is unable to give the cost.

WINCHENDON RESERVOIR.

Bids for this reservoir were received November 25, 1895. It
was built from plans made in 1889, and, as before explained, used
in 1 89 1 in building the Franklin reservoir. The only change made
was to increase the size of the piers from i2xi2toi2xi6 inches.

Like the others, the water to be stored in this reservoir was
from an underground source. Hence it was decided to use a
covered reservoir.

As built, the reservoir has an internal diameter of 69 feet at
the bottom and 71 feet at the top. The depth of water is 17 feet
8 inches. The local rubble masonry wall is 5 feet thick at the
bottom and 2-| feet at the top, and has a total height of 21 feet, 2
feet of this amount being below the bottom of the reservoir. The
capacity to high water line, or the top of the overflow pipe, is about
504,000 gallons.

Two sets of brick piers, laid in Germania Portland cement
mortar, 12 x 16 inches, connected by lintel arches, support two
rings of brickwork, which in turn support the concrete dome at the
center and two circular concrete covering arches. The brick rings
are 12 inches, and the concrete roof is 8 inches in thickness. An
embankment surrounds that part of the masonry wall which is
above the original surface of the ground, and the filling is extended
over the roof and properly graded and seeded to grass.

Test pits were sunk at the reservoir site in order to ascertain
the location and depth of the ledge, which was known to exist. It
was found impossible to entirely avoid the ledge, and considerable
rock excavation was required at the bottom on the westerly side.

The rubble masonry wall was begun in April, 1896. The core
was left until the v/all had been built, when it was removed and
placed in layers and wet and rammed about the back of the wall.
The wall was built of local rubble stone, and considerable difficulty
was experienced in obtaining it of suitable quality. The ledges in
the vicinity were found to be unfit, and the wall is largely composed
of split field boulders.

At the top of the wall a skewback was cut, from which to start
the outer concrete covering arch. A derrick and hoisting engine
were used in making the excavation and laying the wall.

124 ASSOCIATION OF ENGINEERING SOCIETIES.

The ledge was excavated to a sufficient depth to allow 6
inches of concrete being placed on the bottom. The ledge was
more or less disintegrated, and but little of that removed was fit
for use in the wall.

All piers rest on solid ledge, or on large granite blocks firmly
bedded in the bottom.

The piers are laid in Germania Portland cement mortar, the
lintel arches connecting them and the spandrel filling between them
being of American cement brickwork 12 inches thick.

The covering arches and dome at the center are of Portland
cement concrete 8 inches in thickness. The cement used was of
the Germania brand, and the proportions were i of cement, 2 of
sand and 5 of broken stone, not over 2 inches in its longest dimen-
sion. Centering for the entire roof was put in place before any-
concrete was used.

Before the covering arches or dome were started the embank-
ment about the masonry wall was raised to the top of the wall and
thoroughly rammed, thus assisting the wall to resist the thrust of
the arches.

The concrete was put in place in sections bounded by radial
lines. The positions of these sections of covering arches and
dome were such that they were on radial lines extending entirely
across the reservoir from circumference to circumference, thus
tending to transmit any horizontal thrust to the rubble masonry
wall.

The concrete was prepared by a gang of five or six men, who
put it in place as soon as it was thoroughly mixed. The amount
prepared at one time was one barrel of cement with the proper
amount of sand and broken stone.

Enough water was encountered in the excavation for wetting
the bank and for use in making mortar and concrete.

The work of putting the concrete in place began July 14 and
ended July 28.

About 100 cubic yards of concrete were used in the roof, and
a saving of about $700 was made by using concrete instead of
brick.

After the last concrete had been in place fourteen days the
wooden centering was removed and the roof found to be hard and
smooth, and no cracks or settlements could be detected. As the
water in the reservoir is above the freezing point, and as there is a
covering of from 2 to 3 feet of earth over the top, there can be no
action of the frost upon the concrete, and it should last indefinitely.

COVERED RESERVOIRS. 125

At the center is a ventilator consisting of an 8-inch cast iron
sphere perforated with -J-inch holes.

Entrance to the reservoir is had through a 26-inch manhole in
the roof, on the top of which is placed a heavy cast iron cover
secured by a padlock.

The soil on the top and sides of the reservoir was seeded to
grass to protect the bank from being washed by the rains.

A 6-inch vertical overflow pipe connected with a waste pipe of
the same size prevents the reservoir being overflowed. The top of
this pipe determines the high water level of the reservoir.

Water can be withdrawn from the reservoir by the 14-inch
main only to within 6 inches of the bottom at the center. All below
that level must be drawn out through the 6-inch waste pipe, which
can be done by opening a 6-inch gate in the bottom of the reservoir.
This arrangement prevents any sediment from entering the dis-
tribution system. The 6-inch waste pipe passes through the bot-
tom of the reservoir with a slight inclination and comes to the
natural surface of the ground a few hundred feet below the reser-
voir.

On account of the large amount of ground water in the soil at
the reservoir location a hole was made in the 6-inch cast iron waste
pipe, so that it acts as a drain for reducing the level of the ground
water under the reservoir and prevents any upward pressure on the
bottom when the reservoir has been emptied. There is also a 2-
inch composition pipe set vertically in the concrete bottom, making
direct connection between the space under the concrete bottom and
the reservoir. This pipe is about i foot long, and at the top has
an elbow and on it a check valve opening toward the reservoir. In
case the water in the reservoir is drawn lower than the outside
ground water this check valve will open and the ground water
flow into the reservoir, so that no pressure can be exerted on the
concrete bottom.

An underdrain composed partly of 4-inch Akron pipe, laid
with open joints and partly of broken stone, is laid on the inside of
the masonry wall and just below the under side of the concrete
bottom. This collects the ground water and brings it near the
point where the 6-inch cast iron waste pipe passes through the wall.

The sides and bottom received carefully applied plaster and
brush coats of Portland cement, and the reservoir is practically
watertight.

The cost of the reservoir is shown in detail by a copy of the
final estimate of the contractor, Mr. Thomas Hennessey, Holden,
Mass. :

126 ASSOCIATION OF ENGINEERING SOCIETIES.

3472.6 cubic yards of earth excavation @ $0.55

35-2.0 " " rock " @ 1.50

643.5 " " local rubble masonry @ 4.50

69.0 " " Fitzwilliam rubble masonry @ 5.50

3.4 " " Fitzwilliam rubble pier founda-
tions @ 16.00

316.9 lineal feet of 14-in. pipe laying @ .25

285.2 " " " 6 " " " @ .25

27.7 cubic yards Portland cement brickwork @ 18.88

16.6 " " American " " @ 18.88

81. 1 " " American cement concrete on bottom. @ 5.00
98.8 " " Portland cement concrete on roof. ..@ 8.00

464.2 square " Portland cement plaster coat en sides @ .25
411.O " " Portland cement finishing coat on

bottom @ .25

217.0 lineal feet of drain in bottom @ .12

204.0 cubic yards of borrowed earth @ .55

^1,909.93
528.00

2,89575
379.50

54.40
7923
71.30
498.60
498.60
405.50
790.40
116.05

102.7s

26.04

112.20

$8,218.65
Had there been no ledge in the bottom the cost would have been
reduced $446.60, making the total expense $7772.05.

RESERVOIR FOR THE MASSACHUSETTS HOSPITAL FOR EPILEPTICS,

MONSON, MASS.

This reservoir is a circular masonry structure covered with a
dome or roof of concrete. It is 39 feet in diameter at the bottom

Circular Distributing Reservoir, at Monson, Mass., for Massachusetts
Hospital for Epileptics.

and 41 at the springing line of the roof, 20 feet above the bottom.
High water level is at elevation 659.77 above sea level, and i foot
below the springing line of the roof.

COVERED RESERVOIRS.

127

When full the water is 19 feet in depth, and the reservoir con-
tains 178,000 gallons.

It is located about 2800 feet southwest of the hospital buildings.
The elevation of the natural surface of the ground at the center
was 656.2. Before making the final location a number of test pits
were dug in order to decide where the least rock would be encoun-
tered. At the point selected, the ledge was 7 feet below the surface
at the center, and at the bottom the entire excavation was in rock.

The excavation made was 3 feet greater in diameter than the
outside diameter of the reservoir, or 51 feet. The bottom of the
wall, except at the point where the 8-inch outflow and 6-inch waste
pipe enter the reservoir, is at elevation 638.7. At the point men-
tioned the wall is several feet deeper, in order to properly surround
these pipes.

The wall is 4.5 feet thick at the bottom and 2.5 at the top.
It is built of rubble masonry laid in mortar composed of one part

Determination of Dimensions of Steel Band.

of Hoffman cement and two parts of good sand. A portion of the
stone came from the excavation and a portion from a ledge opened
by the contractor on the reservoir grounds. Some stone was also
brought from the Flynt quarries.

When the rubble masonry wall had been carried "to an eleva-
tion a little below high water level a band made of two plates of soft
steel, each 12 inches in width by ^ inch in thickness, was riveted
together in place on blocking, so as to inclose the wall when com-
pleted. The band was 46 feet in inside diameter, and made of ten
plates about 29 feet in length. The plates break joints and have a
splice plate on each side. That on the continuous side is 24 x 12
inches by ^ inch in thickness. That on the other side is of the same
size, but ^ inch in thickness. Each joint has twenty-six rivets ^
inch in diameter. There is a rivet every 3 feet between the joints.

128 ASSOCIATION OF ENGINEERING SOCIETIES.

One coat of boiled oil was applied at the shop and two coats of red
lead after the band was in place.

After the paint was dry the wall was completed inside of the
band, and the band inclosed in masonry or concrete to protect it
from rusting.

The band was furnished in place by Edward Kendall & Sons,
Cambridge, for $248, they being the lowest bidders.

The object of the band is to resist any thrust caused by the
action of the concrete roof.

The dimensions of the steel band were determined as follows :
Two radial sections of the concrete roof were assumed as shown in
diagram, the width of the wedge-shaped piece being i foot, as
measured along the circumference of the masonry wall. The aver-
age weight of the concrete roof, including the earth covering, snow,
etc., was assumed to be 450 pounds per square foot.

The load for this radial section would be ' — = 4725 lbs.

The resultant acts at the center of gravity of the section, or 7
feet from the inside of the masonry wall. The moment about the
point of support would be 4725 x 7 = 33,075 pounds.

This moment is equal to a horizontal moment consisting of the
horizontal thrust on the section, multiplied by the rise of the roof,

or ^725Ji^ ^ 8268.
4

This pressure acts upon each section of the band i foot in

length.

The circumferential stress on the steel band at any point would

be ~ — ^^-^ =: 173,628 pounds.

Assuming 15,000 pounds per square inch as a safe stress to
which to subject the steel band, the area of the cross-section would

, 173628 . ,

be — = 11-57 square mches.

15000 ^' ^

The band used is 12 inches by i inch, with one f-inch rivet
hole out, giving a net area of 11. 12 square inches, which is nearly
the area called for.

In making this computation the tensile strength of the concrete
was disregarded.

The concrete dome or roof has a diameter of 41 feet and a rise
of 4 feet.

According to the specifications, either Dyckerhoff, Germania
or Alsen Portland cement was to be used. The W. N. Flynt
Granite Company, who had the contract, decided to use the latter
brand.

COVERED RESERVOIRS. 129

The concrete is 10 inches in thickness at the springing Hne, and
decreases to 8 inches at the center.. It was put in place on accu-
rately and thoroughly built wooden centering, covering the entire
reservoir. The centering was supported on large chestnut posts,
w'hich rested on a set of hardwood wedges, which were driven out
when the centering was removed. The boarding of the center was
of good quality planed spruce, tongued and grooved.

The concrete was composed of one part, by measure, of Alsen
Portland cement, two and one-half parts of good sand and four
and one-half parts of broken stone, not over 2 inches in its longest
diameter.

The concrete was thoroughly mixed as dry as could be well
rammed, and put in place as quickly as possible. The amount
required for the roof was about 40 cubic yards.

The work was begun about 10 o'clock a.m. November 4, 1897,
and completed at noon of the next day, or in twelve working hours.

As soon as the concrete had begun to set it was covered with 5
or 6 inches of earth to prevent freezing. Afterwards about 2 feet
of soil was put on in the center, increasing to about 3 feet at the
circumference. An embankment was also' built about the part of
the masonry wall above the natural surface of the ground.

On December 3, 1897, the wedges under a number of the
posts supporting the centering were removed. There appeared to
be no settlement of the concrete roof. On December 24 the entire
centering was removed. The concrete roof appeared hard and
smooth. No settlement occurred, and no cracks could be dis-
covered.

The masonry wall was then carefully pointed up, and a -l-inch
plaster coat composed of equal parts of Alsen Portland cement and
sand was put on. The object of the plaster coat was to make the
reservoir as nearly watertight as possible. Later the wall was gone
over with a brush coat of neat Portland cement in the form of a
thin paste.

In building the masonry wall great care was taken to leave no
voids and to have a wall of solid stone and mortar, preferably with
as much stone and as little mortar as possible and still have all the
joints filled. No stone was allowed to extend entirely through the
wall, as this would form a continuous joint through the wall along
which the water might escape.

At the point where the 8-inch outflow pipe and the 6-inch
waste pipe enter the reservoir the wall is carried somewhat deeper,
and is carefully built under and around the pipes. Cast iron
flanged sleeves are secured to both pipes by a lead joint at the

130 ASSOCIATION OF ENGINEERING SOCIETIES.

center of the wall, to prevent the water following the outside of the
pipe through the wall.

On the 6-inch waste pipe, nearly under the manhole, is a 6-
inch T, in which is placed a 6-inch pipe with the upper end at high
water level. On the inner end of the 6-inch waste pipe is a 6-inch
gate. This gate is closed except when draining the lower part of
the leservoir. The outer end of the waste pipe comes to the natural
surface of the ground about 170 feet from the center of the reser-
voir.

Considerable ground water was found in the reservoir excava-
tion. In order to relieve the bottom from an upward pressure
when the reservoir is empty, the bottom of the excavation was
underdrained by placing a layer of broken stone over the top of the
ledge. By means of 4-inch Akron drain pipe the ground water is
brought together under the concrete bottom and passes through
the footing course of the masonry wall and out to the natural sur-
face of the ground through a 4-inch cast iron pipe. Even in the
dryest weather there will be some flow from this pipe, but it is in
no sense due to leakage from the reservoir. It is the natural
ground water which accumulates around and under the reservoir,
and runs off through the drain.

Outside the reservoir is a 4-inch gate on the 4-inch cast iron
drain pipe. By closing this gate the flow of the ground water
from around and under the reservoir is checked, and it will rise to
such a level outside of the reservoir wall that it will escape at some
point.

If the reservoir is emptied when the outside water is above
the level of the bottom, as before mentioned, there will be an
upward pressure on the bottom, which will tend to push it in.
As the area of the bottom is 1195 square feet, the total pressure
would be considerable. If the outside water stood 4.6 feet higher
than the bottom the upward pressure would be 2 pounds to each
square inch, or a total upward pressure of 172 tons. The concrete
bottom is I foot thick, and if the weight of the concrete is called
140 pounds per cubic foot it will by so much reduce the upward
pressure of the ground water, and the net upward pressure would
be about 88 tons.

It is probable that the ground water will stand at a higher level
than that mentioned.

If the 4-inch gate is closed the ground water will form a water
jacket to a certain height and lessen the tendency, if any, to leakage
from the reservoir.

To relieve this upward pressure when the reservoir is empty
and the 4-inch gate on the 4-inch cast iron drain pipe is closed two

COVERED RESERVOIRS.

131

2-inch composition pipes,' with check valves similar to that men-
tioned in connection with the Winchendon reservoir, are provided.
The cost of the reservoir was $5644.08, as shown by the follow-
ing copy of the W. N. Flynt Granite Company's final estimate.
To this should be added the $248 paid for steel band :

820.0 cubic yards of earth excavation, in reservoir....

693.1 " " " rock

40.0 " " " earth " " pipe trench,

within 15 feet of reservoir. . .(<

32.7 " " " rock excavation in pipe trench,

within 15 feet of reservoir. . .(c

426.1 " " " rubble masonry in Hoffman ce-

ment (t

39.8 " " " Alsen Portland cement concrete, in

roof .d

3.2 " " " same, enclosing steel band, and in

cut-off wall (<

48.5 " " " " on bottom and around pipes. .^
0.5 " " " American (Hoffman) cement brick

masonry d

293.2 square " " Portland (Alsen) cement plaster-

ing on wall ((

835.3 cubic " " borrowed earth d

39.0 lineal feet " 8-inch cast iron pipe laying (i

60.0 " " "6 " " " " " (i

47.7 cubic yards of broken strne about under drain and

on bottom d

137.0 lineal feet of 4-inch cast iron pipe laying (under

drain) d

15.0 lineal feet of 4-inch Akron pipe, laid, for under
drain d_

$5,644.08

If there had been no rock excavation the cost would have been
$4263.02, making a reduction of $1381.06.

From his experience and observation, the writer believes that
concrete can be used with entire satisfaction as a covering for reser-
voirs, and at less cost than brick.

If the reservoir is circular the entire centering should be put
in place before any concrete is used. If the covering is of brick it
is often possible to remove the centers before the whole roof is
completed and use them in building another section of roof.

$0.50

2.00

$410.00
1,386.20

•50

20.00

2.00

65.40

5-50

2,343-55

12.50

497-50

6.00

40.00
291.00

8.50

4-25

•35
•35
.80
.80

102.62

292.36

31.20

48.00

1.87

89.20

.15

20.55

.15

2.25

132 ASSOCIATION OF ENGINEERING SOCIETIES.

LOCKS AIS^D LOCK GATES FOR SHIP CABALS.

By Henry Goldmark, Member of the Detroit Engineering

Society.

[Read before the Society, March 24, 1899.*]

The problems of canal construction as a part of the civil engi-
neer's work have within recent years assumed new and unexpected
prominence. Several important canals for a navigation of the first
class have lately been completed, and further projects of un-
paralleled magnitude are now under construction or the subject of
serious discussion.

Among the large works recently finished abroad may be men-
tioned the Manchester, the North Sea-Baltic and the Corinth canals
and the enlargement of the canal prism at Suez and Amsterdam.
In America the most important waterways under construction or
survey are the great drainage canal at Chicago, now nearly finished ;
the rival projects at Panama and Nicaragua, and the equally im-
portant plan for a canal of the first class connecting the Great Lakes
with tidewater.

All this activity is the more striking because for more than
a generation the rapid development of railroads appeared to have
given a death blow to new canal construction, and many existing
canals had suffered a decrease in their traffic or had been entirely
abandoned. There were, however, good reasons for this temporary
decline, which was not due to any inherent weakness in canals as
such, but rather to a mistaken public policy by which their great
advantages were not properly made use of. The superior economy
of transportation by water with vessels of proper design and in
waterways of considerable size is not open to question. The
modern freight steamer on the high seas and our own Great Lakes
carries freight at a cost much less than even the lowest railroad
rates. The tonnage of the lake traffic particularly has of late years
advanced by leaps and bounds.

It is perhaps impossible to reach the same high degree of
economy in the case of canal and river channels, which are neces-
sarily more restricted. But in canals of large cross-section, using
modern vessels propelled by power, the cost per ton mile should
not be much greater than in open water. The real reason why
our canals have decreased so much in relative importance lies in the
fact that in size, in construction and especially in the nature of the

♦Manuscript received April 14, 1899. — Secretary, Ass'n of Eng. Socs.

LOCKS AND LOCK GATES FOR SHIP CANALS. 133

boats used on them, they are many years behind the times, and
represent a phase of development long past in all other departments
of transportation. When operated in competition with the highly
developed railway systems, embodying the latest improvements of
modern engineering, it is not to be wondered at that they have lost
most of their former importance.

The only way in which canal, navigation can be revived is to
put it as nearly as feasible on the same footing as navigation in
lakes and large rivers, by using large vessels, equipped with modern
machinery, in channels of sufficient cross-section to keep the resist-
ance to the movement of the vessels within economical limits. It
goes without saying that canals of this description are very expen-
sive to construct and maintain. There will, therefore, be but few
locations on which the volume of the traffic will be sufficient to
warrant their construction, and we may expect that but few canals
will be built in the future, but they will be works of strictly the
first class.

To the constructing engineer canal building offers many prob-
lems of great interest. The location of the canal, both from a
commercial and a strictly engineering standpoint, requires careful
study, while the excavation of the channel offers a field for introduc-
ing new and ingenious methods for handling earth and rock work
on a large scale. The hydraulic questions involved, such as seep-
age, evaporation, problems of water supply, the flow of water in
open channels, etc., are all interesting as matters of theory, and
offer a rich field for experimental research.

In this paper it is not proposed to take up any of these topics,
but to confine it to the subject of canal locks ; not only because they
are the most important structures in canal construction, but also
because they have not been adequately treated in American engi-
neering text-books.

GENERAL DEFINITIONS.

A canal lock may be defined as a structure which enables
vessels to pass from a body of water to an adjacent one which is at
a different level. As usually built, it consists of an enclosed basin
or chamber provided with gates by which it may be shut off at
either end, so that it can be put in communication alternately with
the upper and lower levels. The method by which boats are passed
through a lock is simple and readily understood.

Besides the ordinary canal lock, various other means for over-
coming diffeiences of level in canals have been proposed at different
times for at least one hundred years past. Among these may be

134 ASSOCIATION OF ENGINEERING SOCIETIES.

mentioned inclined planes and mechanical lifts acting vertically. A
few inclined planes have been in use on small canals both in America
and Europe for many years. Of vertical lifts a large number of
projects have been worked out on paper, but only four of these have
been built and are now in use. They are the hydraulic lifts at
Anderton, England ; Les Fontinettes in France and La Louviere in
Belgium', and the floating lock, so called, at Henrichenburg, in
Prussia. The largest of these is the last-named, which is 230 feet
long by 28 feet wide, with a draft of water of 8 feet. The amount
of lift is 52^ feet.

The operation of these lifts, the oldest of which has been in use
for over twenty years, is quite satisfactory. Their principal raison
d'etre is the saving in water which they accomplish as compared
with ordinary masonry locks. They are certainly of much interest,
and in special locations their use will probably be more general in
the future. The locks are, however, at best the most vulnerable
portion of a canal system, and engineers may well hesitate before
putting a more complex mechanism in place of the simple and mas-
sive masonry lock.

HISTORY.

The invention of the canal lock is one of the few great dis-
coveries by which civilization has been measurably advanced. It
alone has made it possible to navigate many important rivers and
to carry canals over considerable elevations where a single level
canal would be out of the question. The credit for building the
first lock is claimed by both Holland and Italy, but the evidence as
to time and place is conflicting. While in the plains of Northern
Italy the navigable canal is the outgrowth of the shallow irrigating
ditches used from time immemorial, the Dutch canal for boats has
developed from the channels required to drain the low-lying fields
or polders. In both countries simple sluices or head gates were
built long before the enclosed lock with enclosed chambers. Such
gates are sometimes used for navigation, and are often confounded
with true locks by the earlier writers. The first clear and distinct
description of a lock with an enclosed chamber is said to have been
given by Leona Battista Alberti in his book entitled "De re. Aedifi-
catoria," a copy of which was presented to the Pope Nicholas V
in 1452. Simon Stevinus, the celebrated Dutch scientist, also gives
a good account of a canal lock in a treatise published in 1618.

By other writers it is claimed that the first lock was built in
148 1 near Padua, in Italy, while the advocates of Dutch priority
feel confident that true canal locks were in use in the Netherlands
before 1250. It may be added that the common canal lock is fre-

LOCKS AND LOCK GATES FOR SHIP CANALS. 135

quently called the Visconti lock, from its alleged inventor, while
by others the laurels of Leonardo da Vinci, already so ample, are
increased by ascribing the discovery to the great painter. The
exact date is, of course, not very important. It is of interest, how-
ever, to note that lock building, as well as canal construction gener-
ally, antedates the establishment of our profession by several cen-
turies. In hydraulic works of all kinds many successive genera-
tions had accumulated a large amount of practical experience long
before the civil engineer, as such, had come into being. In canal
work a high degree of perfection was reached at least 150 years ago.
Faulty methods in construction and. operation had been gradually
ehminated by the severe test of time and experience, so that the
forms then in use have been followed pretty closely, as least for
small canals, down to the present day.

Within the past fifty years many large locks have been built,
but the principles of their construction are essentially the same as
those followed in the older and smaller works.

Although the ordinary canal lock has often been criticised on
various grounds, it cannot be denied that it has proved itself in
practice an extremely satisfactory piece of mechanism. It is simple
and durable, requires few repairs and is inexpensive in operation.

CLASSES OF LOCKS.

According to their location, locks may be divided into two
general classes : ( i ) locks in inland canals and canalized rivers ;
(2) locks in maritime canals and harbors.

In the first class the difference of level to be overcome is due
to the configuration of the ground, which makes it necessary to
divide up the waterway into a series of pools or reaches at different
levels. The "lift" in this case is practically constant, and the
water pressure against the gates of the lock always acts in the same
direction.

On the other hand, in locks used in harbors and in canals com-
municating with the ocean the difference of level is due to the tides,
and in certain cases to wind action. In the North Sea-Baltic canal,
for instance, there is a complete lock at the east end of the canal
which is in use only about twenty-five days in the year, — at times
when a strong east wind from the Baltic piles up the water in the
outer harbor.

The principal use of locks in harbors is for closing dock
entrances where the range of the tides is considerable. This is the
case on the coasts of England and Germany, and on the Atlantic
coast of France. The difference between high and low tide is
rarely less than 15 feet, while in some localities, such as the ports in

136 ASSOCIATION OF ENGINEERING SOCIETIES.

the Bristol Channel, it reaches 44 feet at certain times in the year.
In these harbors vessels are loaded and unloaded in enclosed basins
surrounded by quay walls, in which the water is kept approximately
at a constant level. These basins have narrow entrances, closed by
one or more gates. In some of the docks, especially those of earlier
construction, there is no enclosed chamber, so that the lock reduces
to a mere pair of gates in the entrance channel. These gates are
open for an hour or so at high tide, and all vessels must pass in and
out at this time. When the tide in the outer harbor begins to fall
the gates are closed, and keep the water in the dock basin from
running out. In order to provide against exceptionally high tides
in the outer harbor, another pair of gates is usually added, which
are built so as to support water pressure acting from the outside.
A further modification where the range of tide is great is the intro-
duction of a "half-tide lock" with a second pair of gates, so that
the pressure on each of them is reduced.

The limited time to which the traffic is confined in this form
of dock entrance is objectionable, and many modern English docks
are provided with complete locks having enclosed chambers, so
that vessels can be locked through between the outer harbor and
the docks at all hours. At high tide the gates are left open for
some time, and the larger vessels usually come into the dock with-
out locking.

The construction of these harbor locks is almost identical with
the locks on large ship canals. In the leading ports of Great
Britain a large number have been built during the last fifty years.
In Liverpool alone there are more than one hundred pairs of lock
gates for openings varying from 40 to 100 feet. As but few large
ship canals have so far been built, it is to the experience gained in
building these large dock gates that we must mainly look for
guidance in designing similar works.

DIMENSIONS.

In designing a complete canal lock the first points to be fixed
are the proper dimensions. These are the width, the length, the
depth of water on the sill and the lift or difi^erence of level between
the water above and below the lock.

The width and length and the depth on sill are commonly the
same for the whole canal, and depend on the maximum size of
vessel employed. On the canal proper it is necessary to make the
prism very much greater than the cross-section of the vessel, say
from four to six times as great, so as to reduce the resistance to
motion throusrh the water to an economical amount. In the locks

LOCKS AND LOCK GATES FOR SHIP CANALS. 137

this is unnecessary. An excessive size involves waste of water,
increases the time required to operate the lock and greatly increases
the first cost. In some cases, where the traffic is very heavy, locks
have been built wide enough to allow two ordinary vessels to be
docked side by side, and long enough to take in several of them one
behind the other. The new American lock at Sault Ste. Marie,
which is 100 feet wide and 800 feet long, is a so-called "fleet lock" of
this kind. The wisdom of this design is doubtful. As the width
and length of lake vessels is constantly increasing, it will not be very
long before all the older and smaller vessels will go out of service,
so that the 100-foot lock will not be wide enough to take in two of
the vessels side by side nor long enough to allow them to enter
"tandem." In that event the large dimensions of the lock will be
worse than useless. The Canadian lock at the Sault, finished in
1895, is only 60 feet wide, but 900 feet long, and appears better
adapted to the demands of traffic.

The probable size of vessels in the future is not easy to fore-
see, and the dimensions to be adopted for designing locks for large
ship canals will vary greatly, according to individual judgment.
Some thirty years ago the largest vessels were steamers with pad-
dle wheels that projected a considerable distance on either side of
the hull proper. To provide for these several locks 100 feet wide
were built in the Liverpool and Havre docks. These are now
wider than necessary. At present few merchant vessels are wider
than 60 feet, although a few of the largest exceed this limit, and
the "Friedrich der Grosse" is 68 feet wide. War vessels have some-
what greater beam, the "Iowa" of the United States Navy being 'jd
feet wide over all.

The locks on the North Sea-Baltic canal are 82 feet wide, while
the new locks at Bremerhaven are to have a clear width of 92 feet,
in accordance with a request of the North German Lloyd Steam-
ship Company. On the Manchester canal 80-foot and 65-foot
locks are used, although a still narrower lock is built at the side
for sm^all craft.

The proposed locks for the new Panama canal are to be 59 and
82 feet wide, and about the same width will probably be adopted at
Nicaragua.

The depth of water on the sill of the lock should equal the
maximum draft of the boats, with an additional clearance of i^ to
2 feet.

The "lift" of a lock is its most important feature. If the
width may be compared to the "length of span" in a bridge, the lift
is analogous to the loading to which the bridge is subjected. The

138 ASSOCIATION OF ENGINEERING SOCIETIES.

. lift or difference of level is fixed by topographical configurations,
though in many cases the location of the canal is affected by the
amount of lift which can safely be used. The inferior limit of the
lift in a lock may be i foot or even less. The upper limit has not
yet been reached. Very few locks with lifts exceeding 20 to 25
feet have ever been built. The greatest lift known to the writer in
an inland canal lock is 30 feet. This lift is used at the new locks
in the St. Denis canal, in France. In the Avonmouth dock at
Bristol, England, the range of the tide is nearly 44 feet, and the
strength of the gates is calculated for a head of 45 feet. This lock
was built nearly thirty years ago, and though the gates are of timber
their operation has been entirely successful.

The question whether lifts as high as 40 or 50 feet are advis-
able must be studied carefully for each separate case, and will
depend on the supply of water, the density of traffic and other con-
siderations, as well as on the structural difficulties involved. Dur-
ing the past year the writer has been engaged in the design of locks
of various lifts up to 50 feet. So far as his plans have been
matured, they show no reason why lifts of 45 or 50 feet could not be
successfully used on locks as wide as 80 feet.

Such great lifts will seldom be needed, as the topography of
the country passed through is almost always such as to make the
majority of locks of moderate lift. Even where a concentration of
the locks at a few points might otherwise be advantageous, this can
rarely be done without flooding too large an area of valuable land.
For this reason the opinion sometimes expressed that the adoption
of mechanical locks which permit the concentration of the lift at a
few points will always result in economy is a mistaken one.

CONSTRUCTION OF THE LOCK WALLS.

The construction of a lock may be divided into three parts :
(i) the foundation, the side walls and the floor, which are gener-
ally built of masonry; (2) the culverts and valves for filling and
emptying the lock, with the mechanism for operating the valves ;
(3) the lock gates and the machinery for moving them.

As in most structures, the nature of the foundation encoun-
tered affects the difficulty of construction to a high degree. For-
tunately, in inland canals the locks can often be located on a solid
rock bottom. In the case of harbors, on the other hand, rock is
rarely encountered, and in many cases the bottom is extremely soft.
The successful operation of the gates requires that the side walls
and sill should remain almost absolutely true to their original lines.
The difficulty of securing this result is greater than that encoun-

LOCKS AND LOCK GATES FOR SHIP CANALS. 139

tered in building an ordinary quay wall. No general directions
can be given as to the best choice of foundation in any given case.
When the bottom consists of a rather firm sand or clay it is usual to
cover the entire site with a layer of concrete of sufficient thickness
to support the upward thrust of the water which may tend to lift
it. This layer of concrete is laid in the dry when this is feasible,
but must usually be deposited under water. The side walls are
built on this foundation, and the portion between the walls forms
the floor of the lock. When the bottom is softer and more variable
piling must be resorted to, at least under the side walls, so that the
weight of the walls may not tend to crack the floor. The problem
of dimensioning the side walls and the floor when the bottom is
soft is extremely complicated.

When built on solid rock a lock wall can be designed according
to well-understood rules in the same way as a retaining wall. Each
wall acts separately, and its weight is carried by the rock bottom
immediately below it. The forces tending to overthrow the wall
are the earth pressure behind it, to which must be added a certain
amount of water pressure, varying with the permeability of the
back filling. In this calculation the lock is, of course, supposed to
be empty and the ground water to stand at its highest level.

When designing a lock to be built on a soft bottom we cannot
calculate the strength of each wall separately, but must consider the
entire cross-section of the lock — i.e., the two side walls and the con-
crete floor — as a whole. This section is subjected to a variety of
forces, — viz, the earth and water pressure on the side walls, the
upward pressure on the bottom of the floor and the walls, besides
the weight of the masonry and of the water in the lock. The
magnitude and distribution of the upward reaction of the bottom
cannot be exactly estimated. It is possible, however, to make a
graphic analysis and draw a line of pressures in the walls and floor
under various hypotheses. By comparing the conclusions to be
drawn from this analysis with practical experience in locks built on
a soft bottom much assistance can be gained in proportioning new
structures. With the usual proportions the line of pressure at the
middle of the floor is quite eccentric. This shows the existence of
a considerable bending moment, which would tend to crack the
floor at the top. Such longitudinal cracks have actually occurred
in a number of harbor locks at the very points indicated by the
theoretical analysis. They are not necessarily of a destructive
character, and after they have been closed with concrete are not
likely to give much further trouble. The structure after fracture
is in a new position of equilibrium corresponding to a new distribu-
tion of pressure on the bottom.

I40 ASSOCIATION OF ENGINEERING SOCIETIES.

Laying concrete under water is always somewhat unsatisfac-
tory. In building the large locks at Holtenau, on the North Sea-
Baltic canal, a simple but elegant method was used for lowering
the ground water level and excluding the water from the lock pit.
Three wells 12 feet in diameter were sunk by compressed air to a
depth of about 15 feet below the bottom of the pit. They were
placed close to and just outside the lock at three of its corners. By
pumping from these wells with centrifugal pumps for a period of
fifteen months the water level over the entire lock was lowered so
that the foundation could be built entirely in the dry.

Compressed air caissons and open wells sunk by dredging have
also been used for the foundations of harbor locks. The method
used is practically the same as that employed for bridge piers. The
locks at Toulon, Dieppe and some other French ports were built
with compressed air foundations, while the Bordeaux lock was
founded on open wells. In the latter case the close proximity of
large warehouses was the reason for choosing this method.

The material used in lock walls is almost always masonry, but
floors of timber construction are not unusual, even in large locks.
Cut stone masonry is generally employed, though rubble with an
ashlar facing is not uncommon. Of late years some locks have
been built entirely of concrete. Among these are the fine locks
recently completed by the United States Government on the Henne-
pin canal in Illinois. The writer has also had occasion to examine
the masonry recently built for the new guard gates in the St. Mary's
Falls canal. This masonry consists of a rich concrete without any
cut stone, and presents a very good appearance. The gates are of
timber, and span a clear opening of 108 feet. This is a greater
width than any known to the writer elsewhere.

The masonry at the ends of a lock must support the pressure
from the gates. The walls at the ends are necessarily thicker than
the side walls of the chamber, and must be built with extreme exact-
ness, so as to fit the gates. Their details will depend on the style
of gate used.

The construction of the masonry is further complicated by the
necessity of inserting culverts for the filling and emptying of the
lock, and also of tunnels for the cables that move the gates and the

pressure pipes connected with the operating machinery.

«

ARRANGEMENTS FOR FILLING AND EMPTYING THE LOCK.

Three different plans are in use for this purpose : ( i ) valves
in the upper gate; (2) side culverts in the lock walls; (3) culverts
under the floor of the locks.

LOCKS AND LOCK GATES FOR SHIP CANALS. 141

The first plan has the merit of simpHcity, and' is generally used
in small locks. The openings are rectangular and placed as low
as possible in the gates, so as to act with the largest possible head.
The valves are simple sluice gates, operated by hand from the top
of the gate. Such openings weaken the gate where the water
pressure is greatest. Another objection is the fact that the water
rushes in with much velocity, and tends to break the cables of
vessels in the lock. Furthermore, the time required to fill a large
lock by valves in the gates is excessive. For this reason such
valves are supplemented or replaced in most large locks by culverts
in the side walls or under the floor. The latter arrangement can be
conveniently adopted only in case of a rock foundation, to which
the floor system can be bolted down to resist the upward pressure
of the water, tending to lift the floor when the culverts are filled.
The most important examples of such culverts are found in the
three great locks at Sault Ste. Marie. In all of these the water is
admitted through large rectangular culverts under the floor.
They are about 8 feet square, and connect with the lock chamber by
a large number of openings along the bottom of the lock. The cul-
verts run side by side, and are built of solid timbers. There are
two culverts in the smaller American lock, six in the larger and
four in the Canadian lock. The head is about 19 feet. The largest
lock is filled in about eleven minutes, using four culverts only.

Side culverts are general in the larger European locks, such
as those in the Manchester and North Sea-Baltic canals. There
is a culvert in each wall about twice as high as it is wide. In the
Manchester canal the size of the culverts is 6 x 12 feet. They dis-
charge into the lock by lateral openings.

In connection with culverts three classes of valves are used, —
viz, slide valves, butterfly valves and cylindrical valves. The first
class are rectangular, and may be built of either metal or wood.
It is desirable that they should move with little friction, and be as
nearly water-tight as possible. On the Manchester canal the Stoney
sluice gates are very successfully used, in which the friction is
largely reduced by a system of roller bearings. In the North Sea-
Baltic canal a similar sliding gate built of timber was adopted. In
American locks butterfly valves revolving on a central axis are
common. They are simple in design and durable, and require but
little power to operate them. The only objection to their use is the
excessive consumption of water, as they cannot be made with a
tight fit. This precludes their use where water is scarce.

Cylindrical valves are in use on many French canals, and have
been proposed for the enlarged Erie canal. They consist of vertical

142 ASSOCIATION OF ENGINEERING SOCIETIES.

Steel cylinders resting on conical seats, and are raised vertically to
admit the water through an annular orifice.

While these valves have many good features, they are quite
expensive, as the amount of water that can pass through any one
valve is comparatively small. Valves are generally operated by
power, the machinery being combined with that for moving the
gates.

LOCK GATES.

Although they represent a relatively small part of the total cost,
the gates are more complex in construction than any other part of
the lock, and on their correct design its successful operation will
largely depend. Considered merely as structures, they present an
interesting field in the theory of stresses and in practical designing.

Every lock with an enclosed chamber must have at least two
gates, — one at each end. Besides this an intermediate gate is fre-
quently added, which permits the working length of the lock to be
shortened so that smaller vessels can be locked through more
quickly and with less waste of water. Quite generally, too, a
guard gate is built at either end to allow the entire lock to be laid
dry for periodic examination and repair.

Lock gates, whatever their detailed design, are really movable
dams, and when closed support the pressure of a considerable head
of water. The standard form used in the great majority of cases
is the mitering gate. This consists of two leaves, each turning on
a vertical axis, like an ordinary door. When closed the leaves meet
at an obtuse angle, the so-called toe posts abutting against each
other in the middle of the lock, while the bottom of the gate rests
against a continuous sill. When in this position the two leaves act
as an arch which conveys the water pressure to the side walls.
The fitting of the gates against each other and the sill is difficult to
make and maintain uniform at all times. A bad fitting may inter-
fere with the proper working of the gates, and also causes the
stresses in the different members to be somewhat uncertain.

For these reasons, among others, many substitutes for mitering
gates have been proposed, and some of them carried into execution.
The more important of these forms may be briefly referred to.

(i) The single leaf revolving gate. This consists practically
of one leaf of a mitering gate long enough to reach across the lock
at right angles ; the gate is supported on the bottom and both sides,
and acts as a girder or truss instead of an arch. The single leaf is,
of course, heavier than the separate leaves of a mitering gate for
the same opening. It requires much more power to move, and also

LOCKS AND LOCK GATES FOR SHIP CANALS. 143

shortens the available length of the lock which can be occupied by
vessels. The cost is about the same as for double-leafed gates.
Single-leafed gates have of recent years been built in France up
to 50 feet in length.

(2) The "Tumble" gate, which also spans the canal with a
single leaf, but revolves on a horizontal shaft fixed at the bottom of
the lock. This form has been used in some of the Erie canal locks
for many years.

(3) Sliding gates. Gates of this kind have been built in dif-
ferent English and continental harbors, and in this country in con-
nection with the Davis Island dam in the Ohio River improvement.
The foreign gates are of iron with closed air chambers, while the
Davis Island gate which spans an opening of no feet is of timber
framing. These sliding gates when closed act as trusses, supported
by the side walls and the sill. They are opened by moving them
sideways at right angles to the lock into a recess constructed in the
masonry wall on one side.

(4) Pontoons. Pontoons are sometimes rectangular gates
like the sliding gates just referred to, although they may also be
built having the curved outlines of an ocean vessel. They are
floated across the lock entrance, and are sunk into position by let-
ting water into tanks provided for the purpose. When the lock is
to be opened they are moved into recesses in the wall. Pontoons
are used generally in dry docks, but are not well adapted for ordi-
nary canals where rapid and frequent moving of the gates is
required. The same may be said of the sliding gates, although the
latter, if properly designed and fitted with a good moving
mechanism, would probably give satisfaction in canal work.

The ordinary mitering gate has, however, in the writer's
opinion, so many strong points, such as lightness and facility of
movement, that it is likely to hold its own even for large locks.

MITERING GATES.

Mitering gates are built of all sizes, from the great gates span-
ning openings of 100 feet down to the smallest guard gates. The
material used in their construction is timber or iron, or a combina-
tion of the two. For small gates timber is in every way preferable,
as the first cost is less, repairs are more easily made and there is no
difficulty in designing gates of simple construction using timbers of
small scantling and length. A number of small iron gates have
been built in different countries, but the prevalent opinion among
the engineers directly in charge of canals seems to be averse to
their general adoption.

144 ASSOCIATION OF ENGINEERING SOCIETIES.

The general use of steel in bridges and ships makes large
wooden lock gates seem somewhat out of date. Metal would
appear to have great advantages as in other engineering structures.
Large iron gates have, as a matter of fact, been in use for over fifty
years, the first wrought iron gate having been built for a 6o-foot dry
dock entrance in the Brooklyn Navy Yard about 1850, while about
the same time similar gates were constructed by English engineers
at Sebastopol, Russia, and by the Germans in the Bremerhaven
docks. It has never been denied that these and later iron gates
have given perfect satisfaction.

It is true, nevertheless, that many English and American
engineers of great experience in lock work remain strongly pre-
possessed in favor of timber gates. In England, even at the present
day, about half of the new gates are built of wood. In the Man-
chester canal green heart timber, a very durable wood brought from
British Guiana, was used exclusively in the fifty-four gate leaves
built, although the cost was much greater than that of iron gates
would have been. Some of the large American gates, such as
those in the new Canadian lock at the Sault, are also built of wood.

Apart from natural conservatism, the reasons which make for
wooden gates are their greater lightness, which makes them easier
to move, and still more the ease with which they may be repaired
in case of a collision. Such accidents are always possible, although
they are rare. It does not seem to the writer that this contingency
is sufficiently probable to make it wise for us to give up the great
advantages of steel gates.

DETAILS OF CONSTRUCTION.

A mitering gate consists of a skeleton or frame and a water-
tight sheathing. The frame may be arranged in different ways,
but there is always a heel or quoin post close to the masonry, a toe
or miter post at the other end of the leaf and two horizontal girders,
one at the top and another at the bottom of the gate. Besides this
there are usually a number of intermediate horizontal girders form-
ing a series of arches or rafters carrying water pressure. In a few
gates vertical girders, which bear against the top horizontal girder
and the bottom sill, take the place of the intermediate horizontals.
The weight of the gate is supported on a vertical pivot fastened to
the bottom of the quoin post, while at the upper end of this post
there is an anchorage which extends into the masonry wall. A
roller traveling on a circular track on the bottom of the lock has in
the past been quite generally used at the outer end of large gate
leaves. This relieves the pivot and anchorage of much weight, but

LOCKS AND LOCK GATES FOR SHIP CANALS. 145

makes distribution very uncertain. The disadvantages of rollers
have led to their gradual abandonment.

TIMBER GATES.

The sheathing is always made of planking with calked
joints. The posts consist of one large timber or may be
built up of several pieces. The horizontals differ in construction
according to the size of the gate. For moderate spans straight
horizontals made of a single timber can be used, but for larger
gates built-up trusses must be employed. Where long timbers can
be had, bowstring girders with wooden tie beams, or preferably with
iron tie rods, are probably the best form to be adopted. As examples
of such girders, the old gates for the 100-foot dock entrances at
Liverpool and Havre and the Weitzel lock at the Sault (60 feet
wide) may be referred to. The gates in this last lock have been
renewed during the past winter. They were designed by Mr.
Alfred Noble, M. Am. Soc. C. E., and completed under his care
in 1881. The iron rods, pivots, etc., were found to be in perfect
condition and have been used for the new gates.

Where long timber is difficult to obtain, the horizontal girders
may be built up of several short lengths framed between vertical
intermediate posts and bolted to reinforcing timbers. Many Eng-
lish gates are built in this way.

IRON AND STEEL GATES.

Iron or steel gates, like timber gates, consist of a frame and a
sheathing, both of metal. The cushions at the quoin and miter
posts and the sill where water-tightness is required are usually
made of wood.

The design of a steel lock gate, like that of any other structure,
is largely dependent on the forces which it has to resist. These
will be different when the gate is opened and when it is closed.
When open, the gate exerts a horizontal pull on the anchorage,
while its weight rests on the pivot. These forces must be trans-
mitted through the gate frame and are readily analyzed.

When the gate is closed the water exerts a horizontal pressure,
which is transferred b}- the gate to the side walls and sill of the
lock. The magnitude of this pressure is easily determined, being
at each point equal to the hydrostatic head. The upper gate is most
strained when the lock is entirely empty. The pressure increases
from o at the top to a maximum at the bottom, and may be repre-
sented by a triangle.

In the lower gate it is o at the top, increasing uniformly to the

146 ASSOCIATION OF ENGINEERING SOCIETIES.

level of the lower pool, and from that point is a constant to the
bottom of the gate. It may be represented by a trapezoid.

The gate can be designed to stand this pressure in various
ways. The most common form consists of a series of horizontal
girders spaced in an approximately equal manner and fastened
securely to the quoin and miter posts. They are further held in
place by vertical frames, intermediate between these posts, which
add greatly to the stiffness of the gate. The sheathing consists of
plates riveted to the horizontals and calked at all joints to secure
water-tightness. This sheathing is required only on one side as
far as the function of the gate as a dam is concerned. It is a very
general practice, however, to place the covering on both sides, form-
ing a series of air-tight compartments, the flotation of v\^hich re-
lieves the pivot and anchorage of weight and makes the gate easier
to turn. Some of the chambers are also filled with water as ballast.

The closed chambers are hard to keep tight and somewhat in-
accessible. For this reason in some of the latest designs, such as
the Cascade locks on the Columbia River and the Plaquemine
locks in Louisiana, both built by the United States Government,
they have been omitted and the gates built with a single skin only.

In beginning the actual design, the first point to be settled is
the rise of the sill, which fixes the angle which the gates make with
the axis of the lock. The rise varies from ^ to } of the wddth in
various locks, but a rise of ^ is perhaps the best, being as economical
as a greater rise.

The next point to be considered is the proper outline of the
horizontals. These are almost always plate girders, and may either
have a straight girder shape or else follow the lines of an arch, the
medial line of which is a circular curve passing through the center
of the quoin and miter posts.

Each horizontal is in equilibrium under three external forces,
— viz, the water pressure, which is uniform and normal to the face
of the gate, the reaction of the other leaf, which is at right angles
to the axis of the lock, and the reaction of the masonry at the quoin.
These two reactions are equal and make the same angle, with a line
connecting the center of pressure at the quoin and miter posts.

If the gate consisted of a linear arch without thickness, a circle
would be the true line of equilibrium for the forces acting on it,
and the arch would be in pure compression, and hence the most
economical shape. On these theoretical grounds, it has generally
been held that an arch gate of circular shape is necessarily the most
economical. This has been stated by many different writers for

LOCKS AND LOCK GATES FOR SHIP CANALS. 147

fifty years back, and the proposition has been reinforced by many
intricate calculations, involving the use of the higher mathematics.

As a matter of fact, the gates are never linear arches, but must
be built as curved beams which are rarely less than 3 feet in thick-
ness, so that the surface submitted to the water pressure is not
identical with the curved axis of the horizontal girder. Further-
more, the center of contact or pressure where one leaf presses
against the other at the miter post is rarely exactly on the medial
line, but, on the contrary, varies considerably on either side. This
difference of position is due both to unavoidable inaccuracy in fitting
and material and also to the change in the length of the gate leaves
at dift'erent times, owing to variations in temperature. As a result
of this, the circular arch is never in pure compression, but also
subject to considerable cross-bending. Besides this, in proportion-
ing engineering structures many practical considerations, such as
the minimum thickness of metal that may be tised, etc., must be
taken into account, so that any general theoretical deduction loses
still more in value.

The only reliable method of comparison for dift'erent shapes
consists in a series of estimates based on actual detailed designs.
By means of several extended estimates of this kind, the writer has
satisfied himself that, at least for locks up to 80 feet in width, the
circular arched gate is no more economical than the straight or
girder shape, while it has many practical disadvantages.

The dimensions of the web and flanges in any given girder are
to be determined by the rules commonly used where there is a com-
bination of compressive and bending stresses.

Another interesting question is the distribution of the total
water pressure over the different horizontal girders. The total
amount of this pressure for the whole gate is perfectly determinate.
In case the horizontal girders were connected by a flexible sheath-
ing, the distribution would be equally simple, each girder getting
exactly the load due to its head below water level. As actually
built, the girders are connected by sheathing that has some stiffness
and by vertical posts that have much rigidity. Furthermore, the
bottom of the gate fits more or less closely against a solid sill. The
stiff vertical members modify the distribution of the load over the
different horizontals, even when there is no contact on the bottom
sill and still more when there is contact, so that the verticals carry
some of the water pressure to the bottom sill. The result is that
the upper part of the gate is more fully loaded, while the lower hori-
zontals are proportionately relieved.

Some interesting experiments on models made by M. Chevalier,

148 ASSOCIATION OF ENGINEERING SOCIETIES.

in France, in 1850, illustrate this point very beautifully. The
mathematical statement of these complex stresses has been at-
tempted by several French engineers, but their methods are very
intricate, and the results, while indicating correct values, hardly
merit extreme confidence.

The method of "Least Work" for solving indeterminate
stresses has been applied by the writer to this question with results
that agree satisfactorily with some measurements he has made dur-
ing the past year on the deflections of large gates.

French engineers commonly design the lower girders of their
gates in accordance with the formulae referred to above, assuming
simultaneous contact at the miter post and the sill at all times, while
in England it is usual to proportion each girder for its full hydro-
static head. As the close fitting at the sill is likely to fail at times,
the English practice seems the safer one, though the upper part of
the gate should be strengthened rather more than is customary in
some of the English gates.

The details of construction in all parts of the gate will, of
course, vary according to the individual judgment of the engineer
in charge.

Many otherwise good gates are unnecessarily complex in con-
struction, showing a lack of familiarity with shop practice on the
part of their designers.

In lock gates, which are machines rather than structures,
facility of operation and freedom from breakdowns are far more
important than first cost. At the same time a gate that is simple in
detail is also likely to be satisfactory in daily use.

MACHINERY FOR OPENING AND SHUTTING THE GATES.

The methods used for opening and shutting the gates can only
be briefly referred to. In large modern locks the machinery is
always operated by power, in order to shorten the time required.
The prime movers are generally turbine wheels, operated by the
water in the canal at the head equal to the lift of the lock. The
power thus generated is transmitted to the mechanism for moving
the gate by water under pressure, by compressed air or by elec-
tricity. In the past water under pressure varying from 100 to 800
pounds has been generally used. Machinery of this kind was first
designed by Sir William Armstrong for English harbor locks, and
includes the use of his well-known accumulator. Most English
plants have been constructed by this firm, and designers in other
countries have generally used very similar forms. The water
under pressure moves reciprocating pistons to which cables are

■ LOCKS AND LOCK GATES FOR SHIP CANALS. 149

attached, or else rotary engines, usually with three cylinders, are
used.

The turning of the gates is generally effected by steel cables
or chains, which are attached close to the miter post near the bottom
of the gate. One cable serves for opening and another for closing.
The cables are brought to the engines on the top of the lock walls
through tunnels built in the masonry. The details of the attach-
ment and general arrangement differ in various designs, but it is
usual to have an independent engine on each side wall.

Although cables and chains have worked very satisfactorily,
they have some disadvantages, and in several recent locks other
appliances for opening and shutting the gates have been adopted ;
thus, in the new locks at Barry, in England, a stiff strut is used
which is attached to the gate above the surface of the water, and
serves both to open and shut it. One end of this strut connects
directly to a plunger that moves in a hydraulic cylinder. This
cylinder oscillates on a double axis, which is placed in a recess built
in the wall approximately at right angles to the face of the wall.
In the North Sea-Baltic canal, and also in the new lock at Ymuiden,
at the west end of the Amsterdam canal, a similar arrangement is
used, but the strut is not directly moved by hydraulic power, but
carries a rack that connects with geared spur wheels.

Quite recently electric motors have been substituted for water
pressure engines, and the use of this power is likely to become
general. Hydraulic machinery in cold climates is always likely to
give trouble, and in some instances it is necessary to use oil in
place of water during the spring and fall before it becomes neces-
sary to cease operating entirely. Besides this the transmission of
pow'er by pressure pipes to distant parts of the large lock involves
expensive construction, and repairs are frequently needed. The
use of the electric current would seem to obviate all these difficul-
ties. In the Canadian lock at Sault Ste. Marie electric motors are
used for opening and shutting the gates, as well as operating the
large valves in the culverts. The operation of this' machinery is
entirely satisfactory, although it seems to be rather complicated.

Electric power has also been adopted for the gates of the new
lock at Ymuiden, on the Amsterdam ship canal, as a result of an
extended series of experiments. We may expect that in the future
most new locks will be operated as well as lighted by electricity.

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

Association

OF

Engineering Societies.

Organized 1881.

Vol. XXm. OCTOBER, 1899. No. 4.

This Association is not responsible for the subject-matter contributed by any Society or
for the statements or opinions of members of the Societies.

THE FLOW OF WATER IN PIPES.

By C. H. Tutton, Member Engineers' Society of Western New York.

The substance of the following paper was originally read
before the Engineers' Society of Western New York, in April, 1896.
There was a very glaring absurdity in it as then prepared which
escaped notice until after it was ready for distribution, and the
author was also taken to task by some of his critics on the charge
of levity. While the present paper may be somewhat open to this
charge, we shall endeavor to avoid much of that used before, con-
fining it to our quotations.

The attempt will be made to show that the Torricellian
formula, v^ = 2gh, is misapplied in the fundamental stages of the
science of hydraulics ; and while it is recognized that the author
may be wrong, he would ask, if such be the case, how can the many
agreements of his deductions, which seem too numerous to be
accidental, with what has heretofore been regarded as entirely
within the domain of experiment, be accounted for ?

Weisbach demonstrated the Torricellian theorem substantially
as follows : If the head h be constant, the velocity of efflux being v,
and the discharge per second being Q, w being the weight of an
unit of mass, the weight of the liquid discharging will be Qw.
The work which this quantity of liquid can perform while sinking
through the distance h is Qhw, and the energy stored by the dis-
charge, whose weight is Qw, in passing from a state of rest to the
velocity v is — Qw. If no loss of mechanical effect take place dur-
ing the passage through the orifice these quantities of work are
equal to each other, whence we obtain v- =: 2gh.

152 ASSOCIATION OF ENGINEERING SOCIETIES.

The more modern demonstration is : Suppose the head h
be constant, then the potential energy of the mass is F = mgh.
The kinetic energy of the issuing mass is E = -|mv^. If these be
placed equal, then v" =:: 2gh; or, in other words, we have the re-
markable result that the velocity of the issuing water through a
horizontal orifice varies directly as the square root of the accelera-
tion of gravity by tivice the head.

From this result it can be shown that the pressure at the orifice
is equal to tlie weight of a column of water whose area is that of the
orifice, and whose height is fzvice the head. Bazin has proven this
false experimentally. (See "Contraction of the Liquid Vein,"
Trautwine's translation, p. 32. )

That the first result is not true is shown in the simplest experi-
ment with an orifice, the quantity discharged never being equal to
the area of the orifice by the velocity as deduced by this equation.

As Mr. Robert D. Napier says {Engineering, Vol. XXI),.
"First of all a theory is adopted, which makes out that a certain
amount of work should be done ; then a double-headed phantom is
invented to do the proposed work ; then, because the work is in
reality not done, it is argued that that arises mainly from the fact
that the phantom is in such a hurry to do its work that it trips itself
up and blocks up the orifice it is trying to get through."

The same gentleman says, in Vol. X, No. i, of the "Proceed-
ings of the Philosophical Society of Glasgow," "I have proved .
about three-eighths of the ultimate velocity and five-eighths of the
vis viva is imparted to the water outside of the plane of the orifice."

M. Bazin (p. 27 of work before referred to) speaks of the
rapidity with which the velocities vary from the plane of the orifice
in a distance equal to its radius from it, when "they are completely
equalized throughout the entire cross-section." He also says, p.
39, that "the formula v = \/ 2g(h -(- y) is no longer rigorously
exact from a theoretical point of view."

Professor Heinemann ( Van Nostrand's Magazine, Vol. VI, p.
198) attacked the thesry above presented, arriving impliedly at
V- = gh, this in turn being attacked by Professor S. W. Robinson,
who defended the original theory. In any event, both of these
require a correction usually expressed by a symbol representing
the so-called coefficient of contraction, deemed essentially one of
experiment, and assuming a contracted vein which Bazin states
(p. 36 of work before quoted) does not exist.

Professor Hele-Shaw, in the Engineer, June 2, 1899, states
that "it is extremely convenient to treat all kinds of resistance as
following the same law, — viz, square of velocity, which the varia-

THE FLOW OF WATER IN PIPES. 153

tion of head or height of surface has been shown to do. But this
is far from being" exact, and an enormous amount of labor has
consequently been expended in finding for all conceivable conditions
in actual work tables of coefficients/' etc.

Now, both of these, and, in fact, all theories so far presented,
imply that the mass above is that directly over the orifice, since they
require a mass equal in area to that of the orifice, transferred
through the height h in each element of time. Is this correct? Is
not our so-called coefficient of contraction a necessity of physical
laws, and susceptible of direct calculation rather than an empirical
constant ?

Suppose A, B be the free surface of a mass of liquid, and O be
a point in the bottom of the containing vessel. Now, all of the
pressure that can possibly be brought to bear on the point O is, by
the principle of equal transmission of pressure, bounded by a hemi-
sphere whose radius is equal to the head. But the center of mass
of this hemisphere is fh distant from the base, whence the potential
energy would be mgf h ; and equating this with the kinetic energy
4m V- we obtain v = V^gfh = .6124 V^gh in the plane of the
orifice. Bazin's experimental value for this coefficient with orifices
4 to 8 inches in diameter is about .604, while Ellis found for larger
diameters about .601. The difference of about i^ per cent, can be
accounted for in the fact that the coefficient above applies solely to
a point, which would be the fundamental constant for horizontal
orifices with a perfect liquid. We also learn from this that the
pressure at the orifice is three-quarters instead of twice the head,
confirming the results of Napier and Bazin. *

This velocity is that immediately at the orifice. At the instant
of passing the orifice an entire release of pressure takes place. The
elasticity of the water, supposed perfect, must now restore it to its
original volume. The original compression was due to a head h,
but three-eighths of this has been used to give velocity at the orifice.
The remaining portion, or five-eighths h, must now be restored in
expansion, which gives the total head h ; and, as 4mv- = mgh, we
obtain for velocity beyond the orifice v" = 2gh, which, as Bazin
states, is entirely gained in the distance r ; but while the first expres-
sion, V =: V^gfh, applies in the plane of the orifice, the second
applies only to the individual particles which have passed through
it. the discharge being free into the air and vertical.

As the present object, however, does not concern orifices
directly, this part of the subject will not be pursued further.

In speaking of this Torricellian theorem as applicable to river
velocities, Major Allan Cunningham, of the Royal Engineers, says

154 ASSOCIATION OF ENGINEERING SOCIETIES.

("Roorkee Hydraulic Experiments," Vol. I, p. 145), "For fully a
century after Marriotte's time this notion (founded on a supposed
but false analogy) proved the most complete hindrance to the
science of hydraulics ; the double float has certainly done one good
service in disproving this notion."

Let us now take up some of the formulae for the flow of water
in pipes, and first the time-honored Chezy formula. (In using the
term pipes understand only a closed conduit which is filled at the
discharge end, consequently the inlet end must be entirely sub-
merged.) M. Chezy's formula was proposed for open channels,
but should be equally, or even more, applicable to pipes.

Adopting the theory of uniform motion, and that in order to
obtain such motion the resistance must be equal to the motive force,
he assumes, first, that the resistances are directly proportional to
the length of the wetted perimeter, multiplied by the length of
channel. He also considers them proportional to the square of the
mean velocity, since by an increase of velocity a greater number of
particles are separated in a proportionally less time, or the total
resistances may be expressed by kv-lp. The motive forces he
assumes proportional to the efl^ective component of the weight or to
agh, a being the area, g the acceleration of gravity and h the fall in
the distance 1. Equating these we obtain kv-lp = agh, whence
v rr ^^^ j^ or calling^ = S, and ^-= R, the so-called hydrauhc

radius

v = C(RS)^.

Instead of analyzing experiments as a whole, analysis to find a
value of C suitable for this equation has engaged the attention of
very many hydraulicians.

It is proper to remark here that the former method of calling
S the sine of the slope is both misleading and faulty. S is the head
or fall divided by the length of the pipe ; it may be the sme of the
slope or may be the tangent. Generally it is neither, but a hybrid.
It is an element designed to take into consideration the total fric-
tional or wetted surface of the pipe, R only taking into consideration
a section. Later writers designate it as the virtual slope.

Suppose a different assumption be made. The fiction of the
hydraulic radius will be preserved, since it has been experimentally
shown that in closed pipes the velocities are symmetrically dis-
tributed around the center of figure. (I am only aware of four
series of experiments on pipes other than circular, and they seem
to conform to this law. In comparing circular sections, any linear
element, as well as a divided by p, could be taken as the unit of
reference.) Assume a plane perpendicular to the direction of flow,

THE FLOW OF WATER IN PIPES. 155

and let us also assume that the mass of water below this plane is
offering a resistance to the motion of that above and is being pushed
by it. We will then have, if we consider R as the edge of some
elementary cube opposed to this pressure, P a R^'. But, according
to the law of free fall, Paha v-, hence v- a R% or v a R?, and
assuming v also to vary with S^ and making C the general constant,

In this shape the formula is used by many river engineers.

TAKE AN ENTIRELY NEW ASSUMPTION,

If we consider the transporting power of the pressure and
have P, the pressure required to just move the cube, whose edge is
R, we have, as above, P a R^. But, as this impulse is proportional
to face area and square of velocity (?), we also have P a v'R",
whence R a v^ and hence P a v®. This may be termed the value
of the pressure as connected with its transporting power, or the
pressure exerted on the mass of water ahead of any section owing
to the velocity of that above it, a cpndition fully realized in pipes
with vertical curves, as inverted siphons.

Now, considering only the ordinary resistances, generally called
frictional, of the pipe, the losses due to entrance, bends, etc., having
been separated, we find that while in solids the friction varies as the
mass, but is independent of the surface, that in liquids it varies as
the surface, but is independent of the mass. We have, then, since
the surface also varies directly as the velocity, f a v a R^, and
knowing from the law of free fall that p a v", we have p « R*, the
value of the pressure as overcoming resistance. But since we must
have p = P, therefore v" a R*, or v a R/'s; and again assuming v
to vary as S^ , which from the general law of free fall we are justi-
fied in doing, we have v ex. R^ S''^, whence we can write

V = CR7/3 S^^.

The way the value of the constant C was originally determined
is as follows : If in the equation of variation v a R73 S^, we

make the first term definite by the introduction of the mass — , the
second member will also become so by the introduction of a co-
efficient of resistance -y-, whence

-- V = 4 R'^ S^= or V = ^ R?^ S'^.

g I WI

This assumption has been opposed on account of lack of homo-
geneousness in the equation. We will grant this lack, provided it
can be shown just what f represents. It is not friction alone; it is
not viscosity alone. The element of weight necessarily enters into
it, as also the element of time. V/e are, however, willing to allow
the expression to stand as empiric until f is analyzed.

IS6 ASSOCIATION OF ENGINEERING SOCIETIES.

While we could say we hunted for a suitable value of C, the
simple way in which we arrived at just the value required on the
first trial is worthy of note.

This form has been submitted by Gauckler, by Hagen, by
Heinemann, by Foss, by Thrupp, by Vallot, and still later by W.
Santo Crimp and C. E. Bruges, but none of whom, to my knowl-
edge, has attempted to justify it theoretically or presented it other
than as an empiric formula for special cases.

If we put the average values of w and g in this, or w equals

r J T

62.42 pounds, g equals 32.16 feet, we obtain v = -> R'^ S^^.

Now, simply for convenience, and in order to use about the
same value of n as given in Kutter's complicated formula (in justice
to the Kutter formula we will state that it was not designed for
pipes), multiply this coefficient by 3, and calling 3f ^ n there results

V =r '^R?^ S'/^

n

a formula which, for ordinary purposes, is equally accurate with
and of as wide application as Kutter's, but which, with his, fails in
extreme cases, n will not rigidly follow his values, yet in many
cases it is even more steady. For values from n = .008 to .018 it
may be taken the same. Getting much above the^e values, either
in Kutter's or this formula, there is no more danger of error in
estimating C direct than there is in estimating n, if we get in the
habit of thinking C as we have of thinking n. If proof be desired,
read the tables of n in Trautwine and Hering's "Kutter," where,
while C varies from 125 to 188, n varies from .0218 to .0452, or C
varying from 45 to 94, n varies from .0296 to .0425. I have used

this formula for nearly six years in the form v = ( -^ ^^ jR^iS^,

as this correction makes it more suitable for small hydraulic radii
(more especially in open channels) when n is considered constant
for the same class of surface. For large R the correction dis-
appears.

With n =: .013 Kutter's value for brick sewers^ the above
would become v =: 118 R^ S^^, while Messrs. Crimp and Bruges
give 124 for the constant term.

Incidentally, it should be stated that it is just as applicable to
open channels as to pipes, under the ordinary assumption that R
equals the area divided by the wetted perimeter.

To make a few comparisons : ,

Mr. J. C. Quintus measured the discharge of the Niagara River
at this place. From his measurements are deduced R = 22.89,
S = .000144, V ^ 4-941 • If we make n = .030 in the formula, this
being Kutter's value for large streams, we obtain the same.

THE FLOW OF WATER IN PIPES. 157

In Engineering Neivs for April 4, 1895, is given the following
experiment on a 21 -inch cast iron main, made in Seville, by Charles
A. Friend: R ^ -4375- S = .0015118, v = 2.951. This would
require n = .0113 in this formula, Kutter's requiring n r= .011.

Desmond FitzGerald, in a paper read before the American
Society of Civil Engineers (see their Transactions for January,
1896), records a series of very valuable experiments made on a
48-inch cast iron pipe known as the Rosemary pipe. Taking three
of these experiments on the pipe after cleaning and applying the
value of n as deduced from Mr. F. P. Stearns' previous experi-
ments on the same pipe, or n = .0108, which we find from Traut-
wine and Hering's translation of Kutter is the same value as re-
quired by Kutter's formula, we find :

R.

S.

V MEASURED.

V CALCULATED.

I.O

.0000182
.0005726
.0026110

-539
3-387
7^245

.608
3-412
7.287

It will be seen that for the very low head this formula, like
Kutter's, does not give qviite such close agreement as for greater
heads.

In the lately talked of Pequannock main of the East Jersey
Water Company, 48 inches diameter, of lap-riveted steel, if we take
the data given by Mr. Hering in Engineering News of January 23,
1896, R =: 1.0, S = .002, V == 4-45, we will find n =: .0155, which
we will also find is the average value of n in Kutter's formula as
deduced from Herschel's experiments on the Holyoke flume of
similar construction. (See Trautwine and Hering's Kutter before
referred to.)

BUT ARE ANY OF THE FOREGOING ASSUMPTIONS CORRECT?

If we desire a formula for a special purpose we find Dr.
Lampe's formula for iron pipes, which may be written
V = 203. 3 R"«'* S°-^^%

and that of William E. Foss, of the Boston Society of Civil Engi-
neers, and given in the Journal of the Association of Engi-
neering Societies, Vol. XIII, for the. same case, which may be
written

V = 191 R""'"- s"••'^■'^

and Professor Osborne Reynolds' formula, given in the proceed-
ings of the Royal Society of London for 1883, which may be written

V = CR^^'^-' S\

158 ASSOCIATION OF ENGINEERING SOCIETIES.

all of which decidedly express that v does not vary either with S-'^
or with R^, unless as particular cases. Professor Reynolds' deri-
vation also shows that k is a variable only for the particular condi-
tion of the surface of the pipe. The formula was deduced by his
system of logarithmic homologues. Varying his process a little,
let us now examine actual experiments, and for the present relegate
theory to the background.

In Colonel Mark Beaufoy's "Nautical Experiments" (1795)
is given the solution of the ordinary exponential formula, which he
calls Garnett's Theorem, and applies to the discussion of his experi-
ments on water friction. That is, if we have an equation of the

r r-v ,1 Log V Log v\

form V = S , then x = . ^ .. ^i

' Log S — Log b

In order to illustrate it, let us take the following four series,
comprising twenty-two experiments on wooden pipes, flowing full :

Of these Nos. i to 5 were made in California by Hamilton
Smith, Jr., on a newly-bored redwood pipe of about 1.25 inches
diameter. Quantity discharged, and therefore v, was determined
by direct measurement; S was determined by an engineer's level,
the head being corrected for loss due to contraction at entrance of
pipe.

Nos. 6 to 13 were made in France, by Messrs. Darcy & Bazin,
being their Series 52, as reported in their "Recherches Hydrau-
liques," on a rectangular pipe of unplaned poplar plank 1.575 ^^^^
wide and .984 feet deep. O was determined by weir measurement
in these experiments, and S was determined by piezometers. Nos.
14 to 21 are by the same experimenters, on the same kind of pipe,
except that it was 2.625 ^^^t wide and 1.64 feet deep. They are
reported as Series 51. O and S were determined in the same man-
ner as the preceding experiments.

No. 22 was made on the Moon Island conduit pipe, in Boston,
by Eliot C. Clarke, and is reported in his work on Boston main
drainage. It was a square pipe of planed plank, measuring 6 feet
on a side. O in this experiment was determined by pump measure-
ment. The value of S here given may not be exact, as it is calcu-
lated inferentially from the data given in his report instead of from
direct record. He records the value of C in the Chezy formula,
giving R and v. It is therefore simple to find S, though the final
figure of decimals may vary to a very limited extent from the truth.

In the fifth column of the table is placed the values of v as cal-
culated by the formula about to be deduced, for comparison with
value of V as obtained by actual measurement, the total difference
being only about one-half of one per cent.

THE FLOW OF WATER IN PIPES.

159

EXPERIMENTS ON WOODEN PIPES.

1

V CALCU-

No

R.
.0263

S.

V MEASURED.

LATED.

ERROR f/,.

I

.02419

1-653

1-752

6.

2

.05094

2.469

2.561

4-

3

.07610

3.008

3-142

4-6

4

. 10306

3-519

3.668

4-

5

•I3I15

3.986

4.148

4-

6

.3028

■000533

1.230

1-255

1.6

7

.001067

1.778

1.789

0.5

8

•001733

2.277

2.291

I.

9

•002733

2.940

2.890

-2.

lO

.003867

3-530

3-449

-2.3

II

.006267

4-350

4.412

1-4

12

.007267

4.626

4-758

2.

13

.008800

5-308

5.246

-I.

H

.5046

.000475

1.667

1.658

-0.6

15

.001076

2.520

2.516

i6

.001899

3-373

3-362

17

.002911

4.226

4.180

-I.

i8

.004272

5.069

5-083

19

.005063

5-528

5-543

20

.005760

5-915

5.922

21

.006614

6-375

6-354

22

1.500

s.

.0008428

4.800

4.560

-5-

Tota

80. 147

80.539

0.5

Now let us examine these experiments and see if we can find a
formula which will represent the entire series, and which can be
expressed in the form v = CR^S>'.

Taking logarithms, Log v = Log C -f- x Log R -)- y Log S,
and for the next state Log v'^ = Log C -(- x Log R -|- y Log S^.

But R and C being constant for the same pipe, we find by sub-
tracting the second of the above equations from the first and solv-

ing for y, y

f.og

or Garnett's Theorem, which expres-

Log S — Log .S'

sion is the equation of a straight line whose co-ordinates are the
logarithms of v and S respectivel}^

Plotting, then, these experiments by logarithmic co-ordinates,
the experiments being shown in circles on the accompanying plate,
No. I, we find that parallel straight lines can be drawn through each
series of experiments at the constant inclination, indicated by the
above formula of y = .51.

Now prolong all of these lines until they intersect the axis of v.
These intersections show the logarithms of the velocities at the point
at which S = i for each different value of R, and where, conse-
quently, Log S = o.* Substituting this particular set of velocities
for V in the original formula we will in all cases have S = i, and
the formula reduces to v = CR". . . . (a) Again taking
logarithms, we obtain in the same manner as before

*There would be a decided flavor of the absurd in this construction if S
represented only the sine of slope.

i6o

ASSOCIATION OF ENGINEERING SOCIETIES.

Log V — Log v^
^ ~ Log R— Log Ri'
therefore plotting the logarithms of R, as shown in double circles
in the plate in connection with these special values of v, we obtain
by the corresponding line, which passes very closely through all of
the points thus located, x = .66. That is, v = CR"' S-'^ . But-
when R becomes i, or its logarithm = o, equation (a) reduces to
V = C or Log V = Log C, or the logarithm of C is found at the
point where the line for R = i and S ^ i crosses the axis of v,
shown on the plate by the larger set of circles.

Reading this logarithm from the drawing, and finding the
corresponding natural number, the complete equation for the case
of wooden pipes becomes

v= 129 R«" S''.

The results of these experiments as calculated by this formula
are given in the table.

Taking these experiments alone, tlie formula v ^ 140 R"**' S'''
will give a little closer results. The reason for adopting the form
given will be seen presently.

By this method the following experiments have been examined :

CLASS.

SERIES.

EXPERIMENTS.

Wooden pipe. — Smith, Darcy and Bazin, Clarke...
Tin pipe. — DuBuat, Bossut

4
4

II

5

37
II

17

4

32
9

6
6

7

22
42

79
32

2X6

Lead Pipe. — Darcy, Iben, Bossut, Provis, Leslie,
Jardine, Couplet, Neville, Hodson

Glass pipe. — Darcy, Smith

New wrought iron and asphalt coated pipe. —
Darcy, Smith, Couplet, Crozet, Tubbs, Row-
land, Iben, Gale, Ehmann, Lampe, Fitz-
Gerald

Coal - tarred, galvanized and lap -riveted pipe. —
Iben, Ehmann, Brush, Herschel

86

New cast iron and cement-lined pipe. — Darcy,
Ehmann, Iben, Russell, Fanning, Friend,
Woods, Stearns, Meunier, Bruce

103
30

142
49

8

Old cast iron pipes (cleaned). — Darcy

Lightly tuberculated, rusted or with slight mud
deposits. — Darcy, Couplet, Iben, Ehmann,
Duncan, Simpson, Leslie, Greene, McElroy,
Meunier, Humblot, FitzGerald, Bailey, Sher-
rerd, Forbes, Coffin

Heavily tuberculated. — Couplet, Iben, Fanning...
Uncertain classification, but supposed earthen-
ware.— Murray, Bidder

Rejected. — Darrach

53
38

Brick conduits. — Tracy, Clarke, Elliott, McElroy,
Artingstall and unknown author

Total. — 12 classes, reported by 44 authors...

153

900

L'pwards of one thousand experiments have been examined
since, with very gratifying results.

THE FLOW OF WATER IN PIPES. i6i

The Darrach series were rejected, as they seem to be interpola-
tions and not experiments ; the value of v increasing in an arithmet-
ical progression with that of S, which is a result manifestly impos-
sible and directly opposed to the results obtained from the other
147 series and 847 experiments. Plate 3 also clearly shows the
impossibility. (On referring to the original paper they will be
found given as "deduced tables." They cannot, therefore, be
classed as experiments.) The Murray series are also of little value,
having been, in part at least, misquoted by Mr. Murray.

These plottings cover diameters from half an inch to 8 and 12
feet, velocities from o. i to 48 feet per second, values of S from
.0000095 to 10.7419 and lengths from 20 feet to 20 miles.

DeVolson Wood, in Vol. VII of the Transactions of the Ameri-
can Society of Civil Engineers, says about hydraulic engineers that
"there is a peculiar satisfaction to them in discarding all that has
been done before and finding fault with all their predecessors, and
especially with those who have written on the subject." Disclaim-
ing such intent, it must be said, with reference to one eminent
scholar who sweepingly condemns the experiments of Iben,
Ehmann, Provis, Leslie and others, that had he examined their
experiments in this light he would have found very striking confir-
mation of the general law, many of them equal, and some superior,
to his own. While no series of actual experiments have been found
worthless, single experiments have been found difficult to analyze
until obtaining a consecutive series of the same class from which
the law of the exponents could be deduced.

Proceeding in this manner with the dififerent classes, and as
shown on the plates in detail, the following table is found for the
values of x and y in the formula v = CR" S-^, in which formula,
speaking generally, n is a coefficient of rugosity dependent on the
mechanical condition of the pipe, and x is a constant of adhesion
depending on the physical constitution of the pipe ; for example,
x for cast iron remains constant at .66, but n varies according to its
roughness.

CLASS.

For wooden pipes and cast iron pipes, either new,
old, lightly or heavily tuberculated, or cleaned.

P'or new wrought iron or asphalt-coated pipes

For tarred, galvanized or lap-riveted pipes

For tin, lead and zinc pipes

For glass and brass pipes

Large brick conduits j

One peculiarity of these exponents immediately appears. In
every case their sum is constant and equal in every case to x -|- y

i62 ASSOCIATION OF ENGINEERING SOCIETIES.

= 1. 1 7, whence the formula can be written v = CR'^''~™ S"'.
(If desired, this can readily be expressed in the simple form
S = C^Q", C^ being a constant varying with diameter and with m,
a form adopted by Foss, Flamant and others.) It will be observed
that Professor Reynolds finds the sum of the exponents of v and R
constant and equal to 3.

If, then, we make the assumption m := ^, we immediately
obtain the formula previously deduced theoretically, or

v = CR?^ S^.

It is therefore claimed that for a single general expression in-
volving the above assumption this formula is of as wide applicability
as any yet presented.

Next as to the value of the coefficients C.

For wooden pipes there is a gratifying uniformity in the value
C = 129.*

For tin pipes the same uniformity is found for C = 192.

For lead pipes the older experimenters are unanimous on
C = 189, while the later ones are just as unanimous on C = 168.

For glass pipe C ■=^ 169 holds in all but a single series, which
drops to C = 141.

In asphalt-coated pipes the largest number of series tend to
C =: 170, although some fall as low as C = 140, and FitzGerald's
experiments on the cleaned Rosemary pipe rises to C = 199.
(Incidentally, the sum of the total experimental values of v on the
cleaned Rosemary pipe is 63.631 feet. Calculated by the formula
v = 199 R "" S'^', they would be 63.643 feet, with a maximum error
in any one experiment of about 5 per cent.)

For new wrought iron pipe C varies between 127 to 165, with
the higher figure predominating.

For galvanized pipe one series only is available, giving
C = 166. This value cannot, therefore, be considered firmly
established.

f For lap-riveted pipes, as in Herschel's Holyoke flume, C = 79.
(The Holyoke pipe sections were about 4I feet long. The Pequan-
nock main sections are about 7 feet long. We could infer, there-
fore, 10 per cent, greater discharge or greater value of C for this, or
say C = 87, which would conform to the single experiment given by
Mr. Hering. It is, however, stated that the joints were found
covered with algae. This might have the effect of throwing it into
the lightly tuberculated pipe class, or v = 105 R**" S-^'. The single

*Since this was written several experiments on wood stave pipe have
been received, indicating a value for C of about 155 in the same formula.
The experiments of Marx, Hoskins and Wing would seem to indicate a
value of .58 for the exponent of S, but we would not yet advise its adoption,
although the difference may possibly be due to the difference in square and
round sections.

fSee note at end of paper.

TPIE FLOW OF WATER IN PIPES.

1C3

record given is deemed insufficient to properly classify it, owing to
the peculiar nature of the obstruction.)

Mr. Morris R. Sherrerd, engineer of the Newark Water
Department, has kindly furnished me with data confirming Mr.
Hering's figures, and also relative to a 36-inch main of similar con-
struction. While difficult to place these from single experiments,
they tend to show that all iron pipe, of whatever nature, tend to the
value V = CR '^'^ S°^ after a few years of service. The 36-inch
main would require C = 129 in this form, being four years old.

*Tarred pipes run very evenly, the value of C varying from
115 to 152, with no particular choice. It should be placed at about
120 for general use. The plate submitted. No. 6, also shows that
the low coefficient in this formula of C = 100 for Iben's "Uhlen-
horst" experiments is probably not due to some unknown obstruc-
tion, as reported, but is entirely due to the nature of the coating.

New cast iron, old cast iron cleaned and cement-lined pipes
vary from C = 126 to C = 158, being very evenly distributed
between these values, irrespective of radii. Benzenberg finds 129
for 60-inch pipe.

For iron slightly tuberculated, or with light mud deposits, C
ranges from 87 to 132, the majority clustering around 105 as an
average value, although the Rosemary pipe shows 117. (Fitz-
Gerald's series.)

Heavily tuberculated pipe ranges anywhere from C = 30 to
C = 85. There is nothing to indicate any preference, as in the
nature of the case there cannot be.

In large brick conduits C has the value 129 when unobstructed.
As many of the experiments in my possession on these were made
on conduits obstructed by numerous shafts, they are not fairly com-
parable with unobstructed pipe. For instance, in the obstructed
Fullerton avenue conduit of the Chicago Water Supply C = 91 ;
for the obstructed Chicago Land Tunnel C = no, while for the
unobstructed Lake Tunnel and the Washington Aqueduct it reaches
129, which is also found by Gaillard's experiments.

The history of an asphalt-coated pipe might be written thus:

New

I year old (or when growing slimy) ,

4 years old (very light tuberculations) ,

6 years old '. ,

8 years old (light tuberculations) ..,

10 years old (average of distribution pipes)

18 ears old I (^'^''y'"g ^•'^^ amount of tuberculation).
25 years old (heavily tuberculated)

v^l75 R-62 S-5a
v=i40 R-es S-51
v=i32 R-66 S-51
V=I24 R'«6 S-51
v=ii6 R-66 S-51
v=io8 R-6« S-51
v=ioo R-^" S-^'
v= 90 R-66 S-51
v= 80 R-66 S-5' or less.

Any of these constants may
vary according; to the charac-
ter of the water in hastening
or delaying tuberculation.

*See note at end of paper.

i64 ASSOCIATION OF ENGINEERING SOCIETIES.

In all of these experiments the total head has been reduced by
the loss of head, due to contraction at entrance, where not measured
by piezometers, by the formula h' =r — -^, o being the coefficient of
contraction.

Some of the varying values of C could no doubt be more closely
harmonized should we take into account the varying temperature of
the water, as did Professor Reynolds, who found that by making a
rectangular shift of the lines representing the relative values of v
and S through horizontal distances represented by the difference of
the logarithms of - pj for any two pipes, and vertical distances repre-
sented by the difference of the logarithms of ~p- in which D is the
diameter of the pipe and P a coefficient of viscosity depending on
the temperature of the water, that better harmony could be obtained.
This consideration has been neglected as a refinement unnecessary
for the purposes of the present paper.

It is also possible that closer results might have been obtained
for some of the cases had a third place of decimals been considered
in the values of the exponents.

Every value of C, x and y here given has been obtained directly
from the drawings submitted.

The graphical solution of the inverse problem, it will be seen,
presents a far less complicated diagram than Kutter's. The process
is as follows : Having assumed a value of C, plot its logarithm on
the axis of ordinates, and draw an indefinite line on the slope x. If
using any particular value of R, at the point where this line crosses
the logarithm of R on the axis parallel to that of the abscissae, draw
a horizontal line back to the axis of ordinates, and from this point
draw an indefinite line on the slope y. The logarithmic co-ordinates
of any point on this line are the logarithms of corresponding values
of S and v. That is, three straight lines and a table of logarithms
solve the question with all its complications, or these lines may be
directly marked with the corresponding natural numbers.

Other simple modifications will readily suggest themselves, as
if total friction head for a given length of pipe is wanted, a line
drawn parallel to the line last found and at a distance from it equal
to the logarithm of the pipe length, measured on the axis of x, will
pass through the logarithms of all friction heads corresponding to
various velocities. The sewer diagram shows how to include total
discharge in cubic feet per second, and how to use all values of
n, R, S, V or O from one plotting.

The original intention in this paper was to take up the subject
of open channels also, including in this pipes flowing partially full.

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SEWER DIAGRAM.

v.- 118 IR ■
DIAMETERS

DIAGONALS. CU FT. PER SECOND. PLATE 13.

AREAS OF PIPES FOR DIAMETERS AS INDICATED.

FLOW OF WATER.

To change value of n and use u me diagram.

THE FLOW OF WATER IN PIPES. 165

as sewers and water conduits, but, as it has already reached a suffi-
cient length, that will be reserved for a future communication. It
may, however be briefly stated regarding open channels that the

formula v = - — R'^ S^^ will apply as long as we can consider
the flow uniform and surface parallel to bottom inclination, but it
will not correctly apply to rapidly rising or falling rivers or to those
discharging against tidal action, on which conditions Kutter's
formula is, unfortunately, principally based.

Note. — The experiments of Rowland on high heads were taken from
Trautwine's "Kutter," but there is reason to beHeve them incorrect, owing
to an error in reduction in the original paper in Vol. XIX, Trans. A. S. C. E.
The error, however, does not affect their classification.

It is stated in the text that for tarred and lap-riveted pipes x := .69, y =
.48. We have allowed this to remain as in the ori-ginal to avoid new plates,
but would state that a much larger field of investigations indicates x ^ .66, y

= -SI-

For tarred pipe C should have about the same value as for cast iron
pipe of the same age, while for lap-riveted pipe it decreases from about 125
or 135 for new pipe to no or 114 for pipe "in service." The author regrets
that his occupation at present is such as to prevent his giving a more com-
plete paper, including many later experiments, which are not even referred
to in the preceding, as in the following list of experiments examined since the
original paper was written :

Wood pipe. — Adams, Hardesty, Henny; Marx, Wing and Hoskins.

Lead pipe. — Reynolds, Rennie, Duncan, Robison, Belidor.

Zinc pipe. — Weisbach.

Brass pipe. — Weisbach, Mair.

Rubber hose. — Fanning, Ellis, Francis, Freeman.

Earthenware. — Kuichling, Bidder.

Wrought iron. — Ketchum, Thrupp.

Cast iron, ooated. — Weston.

Cast iron, tarred. — Benzenberg, Pearsons, Vodicka, Kuichling.

Old cast iron. — Robison, Chapman, Rafter, Duane, Brackett.

Lap-riveted. — Schussler, Hardesty, Herschel, Rafter, Hawks, Adams,
I. W. Smith, Kuichling, Tournadre, FitzGerald, Marx, Hoskins and Wing.

Brick conduits. — Benzenberg, Gaillard, Pasini, Gioppi, Croton.

Linen and leather hose. — Freeman.

Cement-lined. — Bazin, Dumont.

i66 ASSOCIATION OF ENGINEERING SOCIETIES.

THE DESIGN AND CONSTRUCTION OF A MODERN
CENTRAL LIGHTING STATION.*

Bv H. H. HuMTHREY^ Memeer Engineers' Club of St. Louis.

[Read before the Club, October i8, 1899.!]

The Keyes ordinance (No. 18,680), passed by the Municipal
Assembly of the city of St. Louis, Mo., in the fall of- 1896, threw
open the doors to all applicants for underground conduit rights.
Fourteen companies appeared at the first hearing before the Board
of Public Improvements and made formal application for space for
electric wires beneath the surface of the streets.

Among the applicants were several newly-organized com-
panies, and one of them has since constructed its plant. The
Imperial Electric Light, Heat and Power Company first turned
current into its underground system one year ago, October 15, 1898,
and has been in continuous and successful operation since that date.
This paper is a discussion of the design and construction of this
plant, which embodies many interesting features.

After engaging engineers, the first question that confronted
the company was the selection of the system of distribution.

This plant was intended primarily to compete for business in
the down-town or underground district of St. Louis, which is
bounded by Spruce street on the south, Wash street on the north,
the Mississippi River on the east and Twenty-second street on the
west. It was required, however, that the system adopted should
be capable of being extended beyond this district, and, if necessary,
of covering almost the entire city. The success of the three-wire
direct-current low-tension underground system in this and other
countries naturally influenced the engineers in its favor. On the
other hand, the cost of copper for such a system, while not strictly
prohibitive, is still so large as to demand most serious study.

The class of service to be supplied had great weight in the
final decision regarding the system. This service consists largely
of 500-volt direct-current motors, there being also some 220-volt
motors of smaller size. Another important part of the service was
to be arc lighting. The growing popularity of the inclosed arc
lamp indicated that this field would be very profitable. The fur-

*The engravings for the photographic illustrations of this paper have
been prepared without expense to the Association. — Secretary, Ass'n of
Eng. Socs.

tManuscript received October 25, 1899. — Secretary, Ass'n of Eng. Socs.

A MODERN CENTRAL LIGHTING STATION. 167

nishing of incandescent light was by no means of secondary
importance.

In order to reduce the first cost of station equipment and
underground work, both conduits and cables, it was deemed advis-
able that all three kinds of service should, if possible, be supplied
from one generator, delivering its output through one underground
duct and one service cable.

These considerations led to the adoption of a three-wire direct-
current system of distribution, differing in important details, how-
ever, from the methods heretofore employed. 220-volt incandes-
cent and 220-volt arc lamps were both to be used on the sides of
the three-wire system, while 500-volt motors would be connected
directly across the outside wires. The saving in copper over the
usual iio-220-volt system, based upon the same percentage of
drop, is three-fourths. Furthermore, the area which can be sup-
plied from one central station at the same percentage of loss is
increased sixteen times. If in the 110-220- volt system the limit
with a certain drop be placed at one mile from the station in all
directions, an area of 3.14 square miles can be covered. With the
220-440-volt system the distance reached from the station in all
directions is four miles, covering an area of 50.24 square miles.
By the proper use of boosters with storage batteries at the ends of
feeders, such a system may be extended over a district within a
radius of 10 miles from power plant.

The next question in point of importance was the location of
the plant. It would be natural to assume that such a plant should
preferably be located upon the river front in order to secure cheap
water, and upon a railway switch to secure cheap fuel. In this
case, however, n» suitable property was available on the water
front. Furthermore, fuel coming from the Southern Illinois dis-
trict can be delivered by wagon from East St. Louis almost as
cheaply as when bridge and switching charges are paid on carload
lots unloaded at the plant. Very few St. Louis power plants are
located upon railway switches, and one large plant which is so
located is supplied with coal hauled in wagons from East St. Louis.
Under these circumstances the plant should be placed as near the
electrical center as possible. A suitable lot was found at the south-
east corner of Tenth and St. Charles streets, and the plant was
located there.

The designing of a plant which would ultimately utilize to the

best advantage al! the limited space available was next undertaken.

Before entering upon the details of this work, however, one of the

engineers spent some time on an extended trip through the East,

12

t68

ASSOCIATION OF ENGINEERING SOCIETIES.

visiting the large power plants in New York city, Boston, Pitts-
burg, Philadelphia, Buffalo and Chicago, making a study of the
most modern plants in these cities. After much study it was
decided to locate the boilers, dynamos and engines all upon the
street level, rather than place part of the apparatus below street
level, as is frequently done. A study of many different designs led
to the division of the plant longitudinally, east and west, into an
engine room and a boiler room, each extending the full length of
the property ; this plan giving an ultimate capacity of 1*0,000 horse
power.

Hypothetical load curves were next prepared, covering the ser-
vice expected from this plant, including incandescent and arc lights

Fig. I. Exterior View of Station.

and motor service. The three were then combined into one curve
representing the entire anticipated output of the plant under the
heaviest service of the winter months. (See Fig. 13.) A study of
this curve indicated that the number of units in the plant should be
at least five. This number fitted both the minimum load, which was
about one-fifth of the maximum, and provided admirably for reserve.
In case of accident during the peak of the load, the other four units
could take the place of the disabled one by each carrying 25 per
cent, above its rating. In case of the adoption of a storage battery

A .MODERN CENTRAL LIGHTING STATION. 169

sufficiently large to carry the reduced load during the latter part
of the night, and assist the generators during the times of maximum
load, it was deemed safe to reduce the number of units to three, the
battery to be of the same capacity as each of the units.

In designing steam plant it was necessary to determine before-
hand what economical auxiliary apparatus, if any, should be
installed in connection therewith, as all of these affect the capacity
of the boiler plant. The rule adopted by the engineers in deter-
mining whether any species of economical apparatus was worth
installing was that it should be able to earn, under a conservative
estimate of the conditions of service, and taking into consideration
the low price of fuel in this territory, 18 per cent, annually upon its
first cost.

Applying this rule to the consideration of compound versus
simple engines resulted in favor of the compound engine. A
further comparison between compound non-condensing and com-
pound condensing engines showed the ultimate economy to be in
favor of the condensing type. Economy in the use of water, which
is obtained from the city's mains at considerable expense, neces-
sitated the installation of a cooling tower in connection with the
condensing plant.

The application of the above rule to the question of fuel econ-
omizers showed that they would be a good investment.

It was decided to use water tube boilers, as this type gives large
capacity in small space, is absolutely safe, quick steaming, eco-
nomical in fuel and can be had in large units. With good draft they
may be overworked 50 per cent., and under mechanical draft they
may be operated for short periods at double their rating. Down
draft furnaces, of the type which has proven so successful in St.
Louis, were selected. They are capable of burning low grade coal,
running high in moisture and clinker, and may be overworked far
beyond the rating of the boilers. They are also simple, easily,
repaired and not likely to get out of order. The most important
characteristic, however, is that they are smokeless, thus complying
with the city ordinances. They improve the fuel economy, and add
somewhat to the boiler's capacity.

It was decided at the outset to divide the total chimney capacity
into two units, for the reason that the draft would be better at light
loads, and one stack only needed to be built then, as but a part of the
plant was to be installed to start with.

On account of the use of the 220-440-volt system of distribu-
tion and the many economical features of the steam plant, this
station has attracted unusual attention. A detailed description of

170

ASSOCIATION OF ENGINEERING SOCIETIES.

Tenth Street

A MODERN CENTRAL LIGHTING STATION. 171

the apparatus used therein may therefore have more than passing
interest.

BUILDING.

The plant is located at the southeast corner of Tenth and St.
Charles streets, on a lot having a frontage of 142 feet 6 inches on
St. Charles street by 85 feet 2^ inches on Tenth street and 92 feet
3^ inches on the east line. An exterior view of the building is
shown in Fig. i. Fig. 2 gives a sectional view of building, and Fig.
3 a plan of the engine and dynamo room.

The building is of dark red brick, three stories high above the
basement and of same dimensions as the lot above street level.
The area under sidewalks on both Tenth and St. Charles streets is
excavated to the curb line, which forms the outer line of retaining
wall. The second story is omitted everywhere except over the
main office, thus giving a clear height in the engine and boiler rooms
of 30 feet. The third story, which is 15 feet high, is devoted to
store rooms, testing department, etc. The floor of the third story
over the engine room is carried on steel girders, resting upon the
division wall and on brick piers on the St. Charles street side of the
building. The floor over boiler room is supported on I beams rest-
ing on steel columns in front of the boilers, and upon the division
wall and the outside wall of building on the alley side. The entire
structure is fireproof. All floors are of cinder concrete carried on
corrugated iron arches sprung between I beams. The roof of book
tile with composition gravel covering. Engine and boiler rooms
extend the entire length of the building, and are separated by a
division wall having fire doors at all openings. Beneath the engine
room are the storage batteries, extending partly under the sidewalk.
Beneath the boiler room is space for coal storage, ash handling and
the location of condensing apparatus and piping. The floor of
engine room is laid with hexagonal tile, and. the walls for 6 feet
above the floor are wainscoted with marble. The main offices of
the company occupy the Tenth and St. Charles street corner on the
first floor. The private offices are in the second story, directly
above. An elevator at east end of the boiler room runs from base-
ment to third floor.

BOILERS.

There are four Heine boilers. Fig. 4, arranged in batteries of
two each, with one stack between them, and economizers in the
rear of and above the boilers. Each boiler contains 171 3^-inch
water tubes 16 feet long. The total square feet of heating surface
of the four boilers is 10,872. Each boiler has a rated capacity of

172 ASSOCIATION OF ENGINEERING SOCIETIES.

1 1,250- pounds of water per hour with feed water from the econo-
mizers at 200° F., into dry steam of 175 pounds pressure above
atmosphere, and is guaranteed to be capable of developing con-
tinuously one-third more. Efficiency guarantee is 70 per cent, of
the calorific value of the coal at any load between rating and 20 per
cent, above. This is equivalent to evaporating 7.21 pounds of water
per pound of Mount Olive nut coal of 10,600 B. T. U. The boilers
are designed for a working pressure of 175 pounds per square inch,
and tested under a hydrostatic pressure of 250 pounds. The

Fig. 4. Front View of Boilers.

entrainment is guaranteed to be less than i per cent at rating, and
not more than i| per cent, at one-third above rating. Each boiler
is equipped with the down draft furnace. A feature of these fur-
naces which is original with the engineers is making the fire doors
open the full width of the furnace, greatly facilitating inspection
and care of the fires. Two additional Heine boilers of the same
capacity are now being installed.

CHIMNEY.

The present boilers are served by one steel stack. Fig. 5, 7 feet
inside diameter, 140 feet high above street level. The design of
the complete plant provides for another 7-foot or 8-foot stack for

A MODERN CENTRAL LIGHTING STATION. 173

the additional boilers, which are to go in. The lower 10 feet of the
present stack are made of ^-inch steel plates ; the next 20 feet of
f -inch plates ; the next 25 feet of yV -inch plates, and the next 85
feet of |-inch plates. It is self-supporting and unlined. There is
a ladder extending up from the roof of the building, and an orna-
mental platform surrounding the top. The base is supported upon
and rigidly bolted to a massive brick foundation 14 feet deep, and
which is solid except for the ash car passage which extends through
it. The stack is provided at the base with suitable door for clean-
ing. Through the third story of the building it is surrounded by a
sheet steel casing which provides ventilation for the boiler room.
There is an improved draft gauge by which the draft can be read
to thousandths of an inch at eight different points, including ash
pits of four boilers, two breechings, inlet to draft fan and base of
stack.

MECHANICAL DRAFT.

In order to counteract the effect of the economizers in cooling
the gases from the boilers, and to permit crowding when necessary,
a mechanical draft system was installed. It is of the induced type,
the fan being placed directly behind the stack and between the two
batteries of boilers. The bearings of the fan are self-lubricating
and water cooled. This fan is driven by means of a direct-geared
electric motor, designed to be operated at different speeds on either
the 235- or 470-volt circuit. This motor is to be controlled auto-
matically, so as to maintain the steam pressure practically constant,
the regulator slowing down the motor as the steam pressure rises
and increasing its speed as the pressure falls. The capacity of the
fan is sufficient to handle the waste gases from four boilers and
furnish a draft equal to i inch of water where the gases leave the
boilers. It is capable of being speeded in emergencies sufficiently
to give a draft of i^ inches on all four boilers.

FUEL ECONOMIZERS.

There are two Green fuel economizers, each consisting of 320
pipes, the combined heating surface being 7680 square feet. The
economizer plant is capable of heating regularly and continuously
45,000 pounds of water per hour 100° F. when receiving the water
at iio^' F., and with the temperature of the escaping gases leaving
the boilers at not less than 450° F. One-third more water may be
passed through in case of necessity, but of course with diminished
economy. These economizers are designed for a working pressure
of 200 pounds per square inch, and were submitted to a hydrostatic
test of 300 pounds after erection in position. They are provided

174

ASSOCIATION OF ENGINEERING SOCIETIES.

with automatic scrapers operated by electric motors. The econo-
mizer plant is provided with pop safety valves, necessary deflectors,
soot scrapers, doors, dampers, etc. They have pressure gauges at
feed water inlet, also feed water thermometers located one in pipe
at entrance to economizers and one in pipe where water leaves the

Fig. 5. Roof of Plant, Showing Chimney and Cooling Tower.

same; also two gas flue thermometers reading to 1000° F. in smoke
flue ; one where gases enter economizers, and one where they leave.
The necessary dampers are provided for sending the gases from the
boilers either past the economizers and directly out the smokestack

A MODERN CENTRAL LIGHTING STATION. 175

or through the economizers and then up the stack, or through the
economizers to mechanical draft fan and thence up the stack. The
economizers as shown on the plans are located in the rear and above
the boilers, supported upon a substantial iron framework and
bricked in air-tight by 8-inch walls.

COAL AND ASH-HANDLING MACHINERY.

The coal and ash-handling plant is of simple and economical
design, and consists of a system of cars, tracks, elevator and over-
head ash bin. The cinders and ashes from the lower grates drop
directly into a metallic ash hopper under each boiler. Running
east and west immediately under these hoppers there is a narrow-
gauge track. The ashes are dumped from these hoppers into small
cars and pushed by hand along the track to an elevator, on which
they are carried up and dumped into an overhead ash bin, from
which they run by gravity into the wagons in the alley. Any ashes
which accumulate in the stacks may be emptied directly in the cars
in the same manner.

The entire space in front of the boilers in the basement is
reserved for coal storage, the fuel being dumped through open-
ings in boiler room floor. It is taken from this storage room in the
same cars, tracks being provided the entire length of the coal
storage space. It is then hoisted on the. elevator to the floor above
and distributed on tracks over the entire length of the boiler room
in front of the boilers.

STEAM ENGINES.

There are now in operation two engines. Fig. 6, of the Williams
vertical two-cylinder cross compound condensing automatic cut-
off pattern, built by Wm. Tod & Co., of Youngstown, Ohio, and
designed for direct connection to the dynamos and shafting. The
east engine. No. i, is of 750 indicated horse power, and is designed
for driving one soo-kw. generator at the most economical rating
of the engine when operated at a speed of 150 revolutions per
minute, and supplied with steam at 170 pounds initial pressure per
square inch at the throttle valve, and exhausting into a 24-inch
vacuum. Engine No. 2 has double the capacity, and is similar in
design to No. i. The heavy fly-wheels are located between the A
frames supporting the high and low-pressure cylinders. Each
engine is so constructed as to be capable of operating continuously
at double its rated capacity, and for short intervals only at one-
third above its double rated capacity. This additional capacity is
obtained by admitting live steam into the receiver or low-pressure
cylinder. The high-pressure cylinders are steam-jacketed on the

176 ASSOCIATION OF ENGINEERING SOCIETIES.

barrel, and both cylinders on both top and bottom heads. The
receiver is provided with reheating coils of copper. The main bear-
ings are adjustable, and are provided with water jackets. The
guides are water- jacketed on the running side. The cylinders and
all bearings are lubricated by the Siegrist lubricating apparatus,
which delivers the two kinds of oil to the cups under pressure auto-
matically maintained by duplicate steam pumps. They also have
hand oil pumps for additional safety. The cyHnders have flat
multiported valves driven directly from the eccentrics. The clear-
ance is guaranteed not to exceed 6 per cent, in either cylinder.
These engines are provided with shaft governors operating upon

Fig. 6. Engines, Dynamos, Booster. ]\Iagnetic Clutches and Crane.

the valves of the high-pressure cylinders, and capable of varying
the cut-off from 70 per cent, of the stroke back to minus TTr-i"cli
opening. The regulation guarantees are that the drop in speed
with a constant steam pressure from no load to one-third above
rated load will not exceed 2^ per cent. This guarantee also covers
a variation of steam pressure between 160 and 175 pounds with
constant load. The variation of speed will not exceed 3^ per cent,
with the combined changes in load and steam pr&ssure above speci-
fied, either with or without the vacuum. The governor is also
fitted with a special speeding device by means of which the engine

A MODERN CENTRAL LIGHTING STATION. 177

may be brought to the same rate of speed under friction only as
under full load. When running with about 170 pounds pressure
at the throttle, at 150 revolutions per minute and under a constant
load at their rated capacity, the engines are guaranteed not to con-
sume more than 15 pounds of water per indicated horse power hour.

Their principal dimensions: Engine No. i — cylinders 18
inches and 40 inches x 30 inches ; diameter steam pipe, 8 inches ;
exhaust, 15 inches; diameter crank shaft, 12 inches; length of
bearings, 21 inches.

Engine No. 2 — cylinders, 36 inches and 57 inches x 30 inches ;
steam pipe, 10 inches diameter; exhaust, 18 inches; diameter crank
shaft. 16 inches; length of bearings, 28 inches.

Another 1500 horse power engine, designed and built by the
Lake Erie Engineering Works, Buffalo, N. Y., has just been
installed. Dimensions of cylinders, 23 inches and 48 inches x 36
inches ; speed, 120 revolutions per minute.

CONDENSERS, PUMPS AND COOLING TOWER.

The condensing plant consists of one Worthington surface
condenser, one Worthington cooling tower, two combined air and
boiler feed pumps and two circulating pumps of the rotary type.
The rated capacity of the plant is 33,750 pounds of steam per hour,
but it will take care of overloads up to 49,500 pounds per hour with
but slight reduction in vacuum. It is guaranteed to produce a
vacuum of not less than 22 inches at above rating and under the
worst conditions of service ; 25 inches under fair and average con-
ditions, and 26 inches under the best. These conditions vary with
the humidity and temperature of the air. The condenser has
34,000 square feet of brass tube cooling surface.

The cooling tower, &.ig. 7, located on roof is 18 feet diameter,
29 feet high and its filling or cooling surface is composed of galvan-
ized iron pipe cylinders. It has duplicate fans located on opposite
ends of the same shaft drawing air into the tower. These fans
are driven by a belted motor in pent house on top of building.

There are two combined air and boiler feed pumps ; one of
sufificient capacity to handle the water required by the 1500 horse
pow'er engine, and the other of sufficient capacit}^ for the 750 horse
power engine, and two independent rotary circulating pumps of
the same capacities. These pumps are driven by direct-geared
motors, so designed that the speed may be varied at least 33^ per
cent.

There are also two injectors for reserve boiler feeds, each hav-
ing a capacity of 11,250 pounds of water per hour, and capable of
handling water of any temperature below 125° F.

178

ASSOCIATION OF ENGINEERING SOCIETIES.

FOUNDATIONS.

All the foundation work in this plant (except chimney) con-
sists of one part Atlas Portland cement, three parts clean, sharp
sand and seven parts crushed limestone small enough to pass
throusfh a 2-J-inch mesh. The brickwork used in foundations of

Fig. 7. Cooling Tower.

chimney is composed of hard burned brick laid in cement mortar.
The engine and generator foundations extend to a depth of 13 feet
6 inches below the floor line of the engine room, and form one large
monolith extending the full length of the engine and generator
machinery.

A ^lODERN CENTRAL LIGHTING STATION. 179

POWER TRANSMISSION SYSTEM.

The engines and generators are connected by means of a
patented system of power transmission (see Fig. 6), consisting of
quills and internal shafts with double bearings, connected by mag-
netic clutches. The arrangement is intended to make it possible
to drive any one, two or all three of the 500-kw. generators, and
either one or both of the boosters, from the large engine in case of
accident to the small engine. Two generators and one booster
may also be handled by the small engine in case of accident to the
large one.

The generators are connected to the engines by means of mag-
netic couplings, so arranged that either intermediate generator or
booster may be disconnected from one engine and connected to the
other while all are in motion. When it is desired to start up a
generator, it is brought up to speed as a motor and then connected
to the engine by the magnetic clutches.

PIPE WORK.

The entire high-pressure system is designed to operate under
a working pressure of 175 pounds per square inch, and was tested
to 250 pounds hydrostatic pressure. All fittings are extra heavy.
All pipe above 3 inches in diameter has flanged couplings and fit-
tings. All bent pipes are made of steel, and bent hot and of long
radius. All valves on live steam pipes and on the feed water con-
nections under boiler pressure are bronze seated. All valves above
10 inches in diameter are by-passed. The cylinder jackets, re-
heaters, separators, steam headers and the entire pipe system is
drained by means of the Holley system, returning the water directly
to the boilers. There is a combined hot well and oil filter located
between the condenser and boiler feed pumps. All the pipes are
covered with magnesia. A steel exhaust pipe is provided for vise
when condensers are not in service, and extends through the roof
near the stack. Each engine has a Cochran separating receiver
located near the main throttle valve. Oil extractors are located
between exhaust pipe and condensers. A suitable blow-off tank is
provided and connected to boiler furnaces, oil extractors and other
hot water drains, with suitable discharge to catch-basin, which in
turn overflows to sewer.

CRANE.

The engine room is spanned by an electric traveling crane
(shown in Fig. 6) with independent motors on the lifting, traveling
and transfer motions. The capacity of the crane is 15 tons at 10
feet per minute, and it has a maximum speed of 30 feet per minute

i8o

ASSOCIATION OF ENGINEERING SOCIETIES.

at lighter loads. The maximum speed of travel is 80 feet per
minute, and the maximum transfer speed 40 feet per minute. The
motors are of 20, 15 and 5 horse power respectively, and are
designed by the manufacturer as a part of the crane and built sub-
stantially into the framework of the structure. This crane has
proved itself one of the most useful appliances about the plant.

GENERATORS AND BOOSTERS.

There are three 500-volt constant-potential electric generators,
built by the Siemens & Halske Electric Company of America, of the
internal ironclad-armature type. They are designed specially to

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FiG. 8. Switchboard.

fit the system of power transmission adopted. The field frames of
the generators may be slid parallel with the shaft a sufficient dis-
tance for reaching the armature for repairs. The capacity of each
generator is 500 kw. at 525 volts when operated at 150 revolutions
per minute. At this rating the rise in temperature of the armature
will not exceed 40° C. ; of the field, 35° C. ; of the commutator 50° C.
The generators are guaranteed for an overload of 25 per cent, for
two hours, and 33^ per cent, for one hour, with a 50 per cent.
momentary overload without injurious sparking. They will not
fiash at the commutator when the circuit breaker opens at 50 per

A MODERN CENTRAL LIGHTING STATION. i8i

cent, overload. The commutators are of large diameter, insulated
with mica and designed for carbon brushes. The brushes are pro-
portioned for 25 amperes per square inch of contact with rated load,
and have hand wheels for both adjusting and lifting. One megohm
of insulation resistance is specified between conductors and frame.
The guaranteed efficiencies of these generators are as follows :

At 14 load . 88 per cent.

At >4 load ' 92^ "

At '2^ load 931/ "

At full load 94 "

At 25 per cent, overload 93 "

There are two separately excited shunt wound boosters, each
of 50-kw. capacity at 150 revolutions per minute, and capable of
carrying 500 amperes and delivering any voltage from zero to 130
volts. The boosters are of the same general construction and
design as the generators, except that the field frames are divided
vertically. Two more generators of the same capacity are being
made at present by the same company.

SWITCHBOARD.

The plant contains a composite switchboard. Fig. 8, of 2-inch
black marbleized slate, containing three generator panels, one
booster panel, two battery panels, one wattmeter panel, three feeder
panels and one voltmeter panel. These are carried upon an angle
iron frame standing directly upon the floor. Each generator panel
contains two pilot lamps, one dynamo galvanometer, one 1500-
ampere amperemeter, one 600-volt voltmeter, one single pole circuit
breaker, one dynamo field rheostat, three single pole double throw
1 500- ampere switches and one single pole single throw switch.
Each generator panel also contains one special Don Shea patent
field switch, so that generators may be operated either bus-exciting
or self-exciting, as desired.

The booster panels contain the two rheostat handles for the
booster field regulators, two amperemeters and the necessary single
and double pole switches for the proper operation of the plant.

On the battery panels of the board the following instruments
are mounted: Two 1200-ampere double reading amperemeters,
four 600-ampere double reading amperemeters, two 300-volt round
pattern voltmeters, two 5-volt round pattern voltmeters, two 50-
point voltmeter switches, four end cell switch indicators, four
sets of motor contact switches for operating motors on end cell
switches, which are located in the battery room, and the necessary
single pole single throw switches for making the necessary connec-

l82

ASSOCIATION OF ENGINEERING SOCIETIES.

tions between battery, bus-bar and boosters. There are four end
cell regulating switches located in the battery room, each of 600
amperes capacity, with points for connecting fifty end cells. Each
switch is provided with a motor and gearing which are operated
from the battery panel of main switchboard, and the position of the
contact switch is shown at all times by the end cell indicators on
switchboard. These switches may be operated by. hand if desired,

Fig. 9. Storage Battery.

with the motor completely disconnected. Each motor is capable
of handling the two end cell switches on each side of the circuit,
although in practice the two are operated in multiple during times
of heavy discharges.

The wattmeter panel is unfinished at present, but is designed
to carry when completed four 6500-ampere 250-volt wattmeters.

Upon the feeder panels five feeders are connected, each having
an amperemeter and double throw single pole switch of 1500-
ampere capacity on the positive and negative sides and a double
reading amperemeter and single throw single pole switch of 500-
ampere capacity on the neutral cable. The voltmeter panel carries
one 500-volt voltmeter and two 250-volt voltmeters, each with a
suitable switch for connecting to the various pressure wires. Each

A MODERN CENTRAL LIGHTING STATION. 183

panel on the board is surrounded by an ornamental copper mold-
ing, and is lighted by two incandescent lamps. All amperemeters
and voltmeters except those on the battery panels are edgewise
instruments.

There are four bus-bars on the switchboard ; one high posi-
tive, one low positive; one high negative, and one low negative.
There are also positive and negative charging busses. The genera-
tors are so arranged that each generator may be operated on either
high or low bus-bars, either in multiple or separately. For con-
venience in handling, the right-hand switches are made positive,
and. the upper throw of switches connects to the high bus. Each
of the two end cell switches on each end of the battery may con-
nect either to the high bus or low bus, or to the charging bus. The
two boosters in the plant may each be connected either between
high bus and charging bus, low bus and charging bus, or between
low bus and high bus, on either side of the system. The boosters
may be connected in series either between low positive bus and
neutral or between low negative and neutral. These combinations
provide for charging the battery under all conditions of service,
and at the same time maintaining it upon the line as an equalizer
of the pressure. Also, either side of the battery may be completely
disconnected, or the entire battery cut out of service and the balance
of the system maintained by means of the two boosters connected
together in series and operating between the neutral and either side
of the system.

All the electric connections between generator and booster and
switchboard are made of asbestos-covered copper cable run under-
neath the floors and supported upon porcelain holders. The con-
nections between battery and switchboard are made by means of
copper bars, lead-covered and painted with an acid-proof paint,
and supported upon porcelain racks. The battery is connected
through swatches to the bus-bars and outside circuits without the
intervention of either fuse or circuit breaker. Two additional
generator panels of the same design have lately been added to take
care of the additional dynamos contracted for.

STORAGE BATTERY.

There are 280 cells. Fig. 9, of the Electric Storage Battery
Company's accumulators, each containing thirteen positive Man-
chester type plates and fourteen negative chloride plates. These
are contained in lead-lined wooden tanks which are supported on
large porcelain insulators resting upon 4 x 6-inch beams. The
elements themselves in each cell rest upon heavy glass plates, and

13

ASSOCIATION OF ENGINEERING SOCIETIES.

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B5'x6'

A MODERN CENTRAL LIGHTING STATION. 185

are separated from each other by glass tubes. The capacity of this
battery is 2000 ampere hours at a discharge rate of 250 amperes,
and it is capable of maintaining a maximum discharge rate of looo
amperes for one hour. It is guaranteed to give a disci arge of 500
kw. for one hour without a drop in pressure below 1.7 volts per cell.
The normal charging rate is 250 amperes, and the maximum charg-
ing rate 350 amperes.

The battery as mentioned above is located in the basement,
partly under the engine room, partly under the sidewalk, in a cool,
well-ventilated room. The floor is composed of vitrified tile laid
in pitch upon a concrete base.

CONDUIT SYSTEM.

Many were the criticisms hurled at the heads of the city ofifi-
cials when they declared that all of the high-tension electric com-
panies should occupy jointly a single conduit system. However,
the city proceeded upon this line, and issued conduit rights to all
the high-tension companies to- the ownership of so many ducts each
m a joint underground conduit system occupying one side of the
street. On the opposite side the low-tension conduits of the tele-
graph and telephone companies were placed.

It was feared that the joint building, ownership and mainte-
nance of a conduit system by the high-tension companies might lead
to endless litigation, but a liberal application of the "Golden Rule"
to the grouping of ducts and to the location of service boxes and
other engineering details of the work has produced a system of
underground conduits which we believe has few, if any, equals.

The high-tension conduits system consists of 3-inch cement--
lined pipe laid on 5^-inch centers, with i inch of concrete between
pipes and 3 inches surrounding the entire group. All ducts are laid
to drain to manholes. The top layer of ducts enter service boxes,,
which are of two sizes, 3x3 feet and 3x4 feet. Service boxes
are placed at most convenient points for reaching customers, and
their depth is governed by the depth of the conduit at each location.
Manholes (Fig. 11) located at every street intersection, and
oftener where necessary, are of three sizes, 4x4 feet, with 9-inch
walls; 5x5 feet, with 9-inch walls, and 8x8 feet, with 13-inch
walls. In depth they are all designed to be 6 feet 6 inches in the
clear under the roof. They are connected to sewers wherever
sewers could be reached.

The conduit system of the Imperial Electric Light, Heat and
Power Company is shown on map, Fig. 10, which gives the loca-
tion of the power plant, the number of ducts owned by this com-

i86

ASSOCIATION OF ENGINEERING SOCIETIES.

pany in the joint conduit on each street and the location of all man-
holes and service boxes. It will be observed that the main trunk
line runs east on Olive street and west on Locust street. The
north and south trunk line is on Ninth street. The conduits as a
rule occupy every other street in each direction. They were laid
out with the object in view of being able to reach one end of every
alley in the city with the distributing main. It was the intention to
build service boxes only opposite the entrance of alleys and to dis-
tribute entirely through the alleys either by overhead pole lines or
through underground distributing laterals.

Fig. II.

Manhole of Underground System Showing Ducts During
Construction.

The conduit system contemplates twenty-three feeding points,
which are shown on the map marked with the letters from A to V,
inclusive. The entire distribution system consists of two ducts,
providing one duct for a three-conductor cable and one extra duct
for city lighting or other service in the future.

Where feeders were located the number of ducts was increased
to provide for them. The system as planned provides for feeders
of sufficient size so that one of the largest cables would fill one duct,
taking a single cable for the positive and another for the negative
sides of the svstem. A third duct would contain the neutral feeder

A MODERN CENTRAL LIGHTING STATION. 187

and pressure wires. Another duct to contain the three-conductor
main cable, and one duct reserved for future service.

UNDERGROUND CABLE SYSTEM.

While the conduit system provides space for a total of twenty-
three feeders, there have been but five installed at present. They
run from the power house to the points B, H, D, P and V on the
first map. The map shown in Fig. 10 gives the location of these
feeders, the testing boxes, pressure wires, three-conductor mains,
junction boxes and lateral service cables. Each feeder consists of
two 1,500,000 CM. single conductor cables and one 500,000 CM.
single conductor cable for the neutral wire. A pressure wire of
No. 16 three-conductor cable carried in the same duct with the
neutral, and connected to the ends of the feeder, provides means
for measuring the pressure at the feeding point by a voltmeter
located at the plant. The 1,500,000 CM. cable is made up of 127
strands of No. 10 B. & S. gauge copper, insulated with /2"i^ch
rubber and protected by ^-inch covering of lead. The 500,000
CM. cable is composed of 61 strands of No. 11 B. & S. copper,
insulated with g^-inch rubber, protected by ^-inch lead sheath.
The No. 16 three-conductor pressure cable is a solid copper con-
ductor, with ^ig -inch rubber and -jig-inch lead. The neutral con-
ductor is only one-third the size of each of the other wires, since
the entire motor business supplied by the company is connected
directly to the positive and negative wires, and does not affect the
load upon the neutral. It will also be observed that the feeder
cables have all the same carrying capacity, notwithstanding the fact
that some are nearly twice the length of others. The object of
this is to economize conduit space and cost of cables by using the
largest cable that can be conveniently pulled through a duct. Pro-
vision is made at the plant for keeping the pressure at the ends of
all these feeders approximately equal, regardless of their length
and the variation in drop, by running different voltages at the
switchboard.

Each of these feeder cables connects to a single pole double
throw switch on the switchboard without the introduction of any
fuses or circuit breakers. Each feeder goes through two feeder
testing boxes placed at convenient distances along its length, and
at the end connects to the system of mains through copper fuses
located in the junction boxes.

The system of mains shown on the map consists of three-con-
ductor cables of three different sizes. No. i-o is used where ser-
vice is lighter, and No. 2-0 where heavier, and 250,000 CM. where

i88 ASSOCIATION OF ENGINEERING SOCIETIES.

heaviest. The No. i-o three-conductor cables consist of 19 strands
of No. 15 B. & S. copper, insulated with -j^^-inch rubber. The No,
2-0 has 37 strands No. 15 B. & S. copper and the same thickness,
■g^j-inch, of rubber. The 250,000 CM. cable has 37 strands No. 12
B. & S., with Jj-inch rubber. All three sizes of three-conductor
main cables have -J-inch lead cover.

Fig. 12. Five-Way Junction Box. Scale 1-12 Size.

The mains are composed of three conductors, each of the same
size, to provide for better distribution of pressure. The rubber
tape surrounding each conductor was made of a distinguishing
color for convenience in connecting, and very few errors of this
kind were made in connecting together the entire system. At the
points shown on the map junction boxes were placed, which are
shown in detail in Fig. 12, into which these three-conductor mains

A MODERN CENTRAL LIGHTING STATION. . 189

were run and connected to bus-bars through copper fuses. These
fuses are each provided with a small porcelain knob for conven-
ience and safety in handling while fusing up or disconnecting.
The lead sheaths on the mains were divided and brought up
through the bottom of the junction boxes and sealed water-tight
by means of special stuffing boxes. The lead joint at the point of
division outside the box was wiped water-tight. The cover of the
junction box is screwed tight upon a rubber gasket by toggle bolts,
making a thoroughly water-tight box.

The feeder testing boxes referred to above are similar in
design to the junction boxes as shown in Fig. 12, although some-
what smaller and not so deep. They provide convenient means for
opening the feeders for testing, the location of trouble or the mak-
ing of repairs. Connection is made in these boxes by heavy copper
links, which are not in any case intended to act as fuses.

The lateral service cables connecting from the underground
mains to the basement of the customers' building are similar in
design to the three-conductor mains, differing only in size and
corresponding variation in thickness of rubber and lead. They are
joined to the mains in the service boxes by means of a three-con-
ductor soldered joint, which is carefully insulated with rubber,
thoroughly taped and protected by a cast iron box. This box is
then filled with an osokerite compound, thoroughly insulating and
preserving the joint from all contact with moisture or other deter-
iorating substance. The insulation resistances of these cables were
guaranteed as follows :

No. 16 B. & S. three-conductor, 1000 megohms per mile.

No. o, 2-0 and 250,000 C.M. three-conductor, 750 megohms per mile.

500,000 C.M. single conductor, 500 megohms per mile.

1,500,000 C.M. single conductor, 400 megohms per mile.

For a break-down test the entire system was submitted to 3000
volts alternating current, and found to withstand this test satisfac-
torily. The insulation guarantees were also found satisfactory
under accurate tests.

The insulation resistances were all measured by means of the
capillary electrometer designed by H. C. Burgess, of the Univer-
sity of Wisconsin, and described by him at the Omaha meeting of
the A. L E. E. The results were found to be highly satisfactory.
It is an extremely sensitive instrument, but is unaffected by mag-
netic influences or by the jarring of building. The only precau-
tion found necessary was the great care essential to avoid surface
leakage. Resistances were measured as high as 2000 meghoms.

1 90

ASSOCIATION OF ENGINEERING SOCIETIES.

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A MODERN CENTRAL LIGHTING STATION. 191

The voltage used throughout most of the tests was 100 volts,
obtained from a chloride of silver battery. Attempts were made
to use a dynamo current from the local power circuits, thus mak-
ing the test at 500 volts the maximum pressure intended to be car-
ried in use. The attempt was a failure, due to the unsteadiness of
the local power circuit and the consequent disturbance due to con-
denser effect in the cables. This instrument can be put to a
variety of uses, although we believe this is the first instance where
it has been used commercially for testing an entire system of under-
ground cables. We have checked its results very closely with a
galvanometer, using the deflection method, but the annoyance and
delay incidental to the use of the galvanometer in this work pre-
vented more than a very occasional checking.

INSIDE WIRING.

The entire inside wiring is done on the two-wire multiple arq
plan. The lateral cables entering the basements of the customers'
buildings are three-conductor cables, furnishing a constant poten-
tial supply of electricity at either 235 or 470 volts. All electric
power service is connected to 470 volts, and the inside wiring is run
open and supported on porcelain knobs, with rubber-covered wire.
The incandescent and arc lamp wiring is taken off one or the other
side of the system at 235 volts and run with rubber-covered wire
either on porcelain knobs or cleats or concealed in an approved
conduit system. All of the old-style iio-volt cut-outs were re-
placed. Specially designed tablet boards with terminals properly
spaced for the higher voltages, and with inclosed fuses, were used
throughout this work. All of the old sockets were replaced with
the latest design of porcelain sockets, and where defective cord was
observed it was replaced by an approved rubber-covered flexible
cord. All of the inside wiring having been gone over in this way,
and cleared of grounds and brought up to the latest standard of
practice, has resulted in decreasing, rather than increasing, the fire
risk following the introduction of the higher voltage system.

INCANDESCENT LAMPS.

The incandescent lamps used on this system are of the 235-
volt type, mostly of 16 C.P., although some 10 C.P. and some 32
C.P. are in use. Also small candle power decorative series lamps.
The lamps are all Westinghouse cap and porcelain base. The fila-
ments are either double, two in series, or coiled in several convolu-
tions. This characteristic is due to the extra length necessary on

192 ASSOCIATION OF ENGINEERING SOCIETIES.

a lamp of this voltage. The lamps were bought under guarantees
regarding efficiency, life and the maintenance of candle power,
which were entirely satisfactory to the purchaser. In practical
operation the light has been entirely satisfactory to customers, and
they compliment the character of incandescent service furnished.
There were at first minor mechanical and electrical defects, how-
ever, such as the sagging of the filament until it touches the glass
where lamps are not placed in a vertical position, and the short-
circuiting of leading-in wires when a filament burns out near its
support, all of which have been remedied in later lamps. There
have, however, been no accidents or fires resulting from these
causes.

ARC LAMPS.

In the original design of this plant, begun fully three years
ago, it was anticipated that its principal business would be power
service, and that arc lighting would not exceed 15 per cent, of the
total service. The introduction, however, of the inclosed arc lamp
and its remarkable popularity, due to the steadiness of the light and
the facility with which its service is metered, has so increased the
demand for arc lighting that the arc service is at present a very
important part of the company's business. It was believed at the
time that the plant was designed that arc lighting might be made
secondary to both the incandescent and motor work. The 235-volt
inclosed arc lamp was therefore adopted on account of its con-
venience, one light being controlled independent of all others. It
has been found by experience that two arc lamps burning in series
on 235 volts give better service than the single lamp. In .cases
where a single lamp must be used a satisfactory light has been
obtained by increasing the current to 3^ amperes.

MOTOR SERVICE.

The entire power service is taken from the outside wires of the
system at 470 volts. These wires inside of the building in all cases
are treated as high-tension circuits. It might be surmised that
complaint would be made regarding the power service on account
of this reduction of voltage on 500-volt motors. This has not
proved to be the case. The motors having been previously used
upon systems varying in voltage from 450 to 550, the users of
power were educated to expect a considerable variation in the speed
of thdir motors. With a steady pressure of 470 volts at the motor
terminals, none of the company's customers have complained re-
garding their power service.

A MODERN CENTRAL LIGHTING STATION. 193

LOAD CURVE.

It may be interesting to submit a preliminary load curve of
this plant, prepared by the engineers and submitted to the company
two years and a half ago, and to compare it with an average load
curve of the plant at present. We have reduced the scale of the
former and plotted them side by side on the same sheet. These
curves are shown in Fig. 13. Their correspondence in shape is
interesting. Their points of difference are explained by the in-
crease in the arc business above referred to. This curve also shows
one of the great advantages of the storage battery. The entire
plant is shut down from one o'clock until five in the morning, and
the load carried upon the battery. The machinery is then started
and the battery charged during the forenoon, allowed to float upon
the system during the afternoon and discharged during the peak in
the evening, as shown upon the shaded portion of the curve; and
again charged considerably during the first half of the night before
shutting down. Interesting features are the large all-night load
and the comparatively low peak or maximum load. The average
output for twenty-four hours is 2198 amperes, which is 39.27 per
cent, of the maximum load.

SPECIAL FEATURES.

The distinguishing features of this plant which marked it as
advanced engineering practice are :

First. The 220-440-volt system of distribution.

Second. The entire system is underground.

Third. The battery equalizer and auxiliary.

Fourth. All subsidiary apparatus is electrically driven.

Fifth. Fuel economizers with induced mechanical draft.

Sixth. Condensing apparatus with cooling tower.

(a) The wisdom of selecting the double voltage system will be
appreciated when it is stated that the saving in copper alone in the
district covered by this plant is equal tO' half the cost of the build-
mg and entire station equipment. This system was almost un-
known at the time of its adoption here, but several plants using it
have since then begun operation in Europe, and another large instal-
lation is being erected in this country. The system is reliable, safe
and satisfactory in its service to the public.

(b) The undergrounding of all wires is the ideal method of
distribution as regards pubhc safety, reliability of service and low
depreciation and repairs.

(c) The value of a storage battery as an equalizer of pressure
and as an auxiliary to the steam plant is universally admitted. It

194 ASSOCIATION OF ENGINEERING SOCIETIES.

has proved indispensable on many occasions in this plant. Its
readiness to take all burdens thrown upon it, whether accident to
plant, short circuit in underground cables or sudden demand for
light caused by a thunder storm, needs only to be experienced to be
appreciated.

(d) Driving all boiler feed, circulating and air pumps, elevator,
fans, etc., by electric motors saves the condensation in all subsidiary
steam pipes, as well as avoids the wasteful use of steam incident
to this class of apparatus. By using steam only in the large cylin-
ders of the compound condensing engines and driving all minor
apparatus by motors, it is estimated that a saving of about lo per
cent, on the entire output of the plant is realized.

(e) Fuel economizers give all the water entering the boilers
an additional temperature of ioo° F., which effects a saving of
about 9 per cent, in the use of fuel. With coal at $1.50 per ton,
they will earn annually about 25 per cent, on their cost.

(f) With all losses deducted, it appears that condensing appa-
ratus as here employed make a saving of from 15 to 20 per cent, in
fuel, thus earning a large return on its cost.

The entire station equipment was included in one contract,
under rigid guarantees from the contractor covering the efficiency
of the plant as a whole. A definite cost of coal per kilowatt hour
delivered to outside circuits from the switchboard was guaranteed
under a forfeiture in case of failure, with an equal bonus for
increased efficiency above the figure specified. It was intended to
give in this paper the results of these tests, but, as they are not
completed, no report can as yet be made.

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

Ass

OCIATION

OF

Engineering Societies.

Organized 1881.

Vol. XXIII. NOVEMBER, 1899. 0 O/^ ^°^

This Association is not responsible for the subject-matter contributed by any Society or
for the statements or opinions of members of the Societies.

ALTERNATING-CURRENT POAVER MOTORS.

By W. a. Layman, Member Engineers' Club of St. Louis.

[Read before the Club, April 5, 1899.*]

Commercial applications of the electric current are broadly
divided between, first, those involving direct current ; second, those
involving alternating current. Both forms of current are so well
understood, and the development of apparatus for the utilization of
them is so well advanced, that, within certain limitations, either
may be used for a great variety of purposes. Examples of this
are to be found in arc lighting, incandescent lighting, power motor
work, street railway service, electric heating apparatus, etc. It
cannot be said that either form of current can be used with equal
facility and economy in these several directions, but development
has advanced to such a point that prominent electrical men are not
able to agree on the exact dividing line where the advantage of one
form of current ends and that of the other begins. Remarkable
strides have been made in alternating-current applications, and
results are now accomplished with this current that a few years ago
were declared not only improbable, but impossible. Notably is this
the case in the power motor field. A decade ago the alternating-
current motor was little more than a laboratory plaything; to-day
its practical and efficient adaptability to power work of all kinds is
generally conceded.

It may be incidentally recalled that there was much controversv
as to whether the great Niagara plant should generate direct or
alternating currents, all arising from the claim that there was no
certainty of ever having a commercially practicable alternating-

*Manuscript received October 4, 1899. — Secretary, Ass'n of Eng. Socs.
14

196

ASSOCIATION OF ENGINEERING SOCIETIES.

current power motor. To-day this power plant is generating forty
to sixty thousand horse power, all in alternating current, and a
large part finds application in power motor fields.

(a) difference between direct and alternating currents.

If there exists in a given space what is termed a magnetic field,
and if an electrical conductor is quickly moved across this space in
a direction angular to the direction of the magnetic lines of force,
as they are technically called, an electric pressure is generated in

Figs, i, 2 and 3.

this conductor ; and if the conductor is a closed loop, under proper
conditions as to algebraic relation of the pressures created, an
electric current will flow around the loop.

In Fig. I such a magnetic field, with a loop of wire revolving
in it, is shown. Here the plane of the loop is parallel to the direc-
tion of the lines of force, and in its rotation, in the direction indi-
cated by the arrow below the figure, the loop is cutting across the
lines of force and generating a current flow, as shown by the two

ALTERNATING-CURRENT POWER MOTORS.

197

arrow-heads on the sides of the figure itself. In this position the
loop is cutting these lines of force at the maximum rate of speed,
and therefore generating its maximum pressure. As the plane of
the loop revolves toward a position at right angles to the lines of
force the rate of cutting decreases, and when the horizontal position
is reached, as in Fig. 2, this rate of cutting is zero. As the rotation
further continues (Fig. 3), the sides of the loop begin to cut the
lines of force in the reverse direction, thus generating pressures and

Fig. 4.

Fig. 5.

currents of opposite sign to those in Fig. i, as indicated by the
arrow-heads.

It is apparent that a loop so revolving generates a pressure and
also a current wave which changes sign as the cutting, relative to
the direction of the lines of force, is changed, rising slowly from
zero to a maximum positive, and then back through zero to a
maximum negative. Such a wave, diagrammatically plotted with
reference to time, is shown in Fig. 5.

198

ASSOCIATION OF ENGINEERING SOCIETIES.

Figs. 4 and 6 illustrate an extension of this principle to the
dynamo electric machine. N and S represent the magnetic poles,
m the space between v/hich there exists a strong magnetic field.
The loop of wire in Fig. i now becomes the revolving armature.
Instead of being closed upon itself, however, it is open at one end,
and the open ends are connected to revolving rings. Upon these
rings brushes bear which carry the current out into the exterior
circuit and back again. Through such an exterior circuit, with
the construction shown in Fig. 4, a true alternating current would
flow, as is shown in Fig. 5. If in such a dynamo the loop revolves
at the rate of eight thousand complete turns per minute, the cur-

FiG. 6.

Fig. 7.

rent will be one of sixteen thousand alternations, or half waves,
per minute, which is one of the standard frequencies of commercial
alternating current of to-day.

To produce direct current, or current in which the flow is
always in one direction, and of practically constant magnitude, it is
necessary only to substitute for the two revolving rings of Fig. 4
one split ring, as shown in Fig. 6. By so placing the brushes
(bearing upon the two half rings) as to cause them to stand on the
breaks in the ring when the armature loop is in the zero generating
position, a reversal of the negative portion of the alternating wave
of Fig. 5, in so far as the external circuit goes, is accomplished.

ALTERNATING-CURRENT POWER MOTORS.

199

By this reversal a single loop of wire would generate a form of
current such as is illustrated in Fig. 7. This would be uni-direc-
tional, but pulsatory in character. To reduce this from such a form
to a true direct or constant-pressure uni-directional current requires
but a multiplication of generating loops, the commutator being still
further subdivided to provide two connections for each loop. The
external circuit is therefore in contact with the ends of any one loop
through a small portion of a revolution only, and the efifect is to
send out into the circuit only the high-pressure sections of a great
many waves, as shown in Fig. 8.

If it were desired to generate two independent alternating-cur-
rent waves, this might be done by introducing independent arma-
ture loops, displaced from each other by a definite angle. If this
angle were 90°, two such loops would generate pressures in quadra-

^Ue^t %t'tv^c

Fjg. 9.

ture, or differing in phase by 90°. Such waves, plotted, would
near the relation shown in Fig. 9. Similarly, three independent
loops set at 60^ to each other would be made to generate, by proper
connections, currents differing in phase by 120°, as shown in Fig.
]0. In this manner are produced the two-phase and three-phase
currents of practical application to-day, these currents being illus-
trated in Figs. 9 and 10 respectively.

(b) direct- and alternating-current motors.

Similarly, I may briefly discuss the fundamental differences
between direct- and alternating-current motors.

A very early development in the application of electric current
Avas the discovery that both forms of dynamo, as shown in Figs. 4
and 6, were reversible in process. That is, with a given magnetic
field and a source of current from the outside, each form of arma-

200

ASSOCIATION OF ENGINEERING SOCIETIES.

ture would, with its corresponding form of current supply, run as a
motor under proper conditions. With Fig. 6 the limiting condi-
tion was that the brushes should be so set upon the commutator as
to send the direct current into any given armature loop at that
instant when this loop occupied such an angular position with
reference to the direction of the lines of force of the magnetic field
as to provide a turning couple between the lines of force and the
loop, this action arising from the fundamental consideration that
magnetic lines of force attract or repel conductors carrying electric
currents, according to the direction of the flow of the current in
the conductor.

Fig. id.

/ / / //

Fig. II.

In Fig. 4 the limiting condition was to have the loop revolving
at such a rate as to cause it to move into the position of reverse
cutting of lines of force simultaneously with the change of direction
of flow of the current supply. In other words, the loop had to
revolve in step with the alternations of the current supply, other-
wise the attractive and repellent forces would neutralize or inter-
fere with each other. Such a motor, therefore, had to be brought
up to synchronous speed, as it is termed, before it would run with
load. For several reasons, other than this great disadvantage of

ALTERNATING-CURRENT POWER MOTORS. 201

not being able to start, the synchronous motor was not deemed com-
mercially practicable for power work in general, and even to-day
has only limited uses.

The next step was to endeavor to make an alternating-current
motor along the lines of Fig. 6. In other words, it was attempted
to use the direct-current motor on alternating currents. Since the
direction of rotation of the armature of a direct-current motor is
the same, so long as the relation between the armature windings
and the field windings remains unchanged, it was assumed that the
motor could be easily used on alternating currents.

If sudden changes of direction of the current were to occur at
long intervals of time apart no serious consequence would result,
and the motor might prove satisfactory ; but with periodic changes
of direction of great rapidity, such as would exist with an alternat-

ing current, a new element is introduced. JVith an alternating
magnetic field currents may be generated in stationary coils of wire.
An electric current flowing through any wire sets up a magnetic
field around the wire. If this current is alternating, an alternating
field follows, the lines of force expanding and contracting in con-
centric circles with each alternation of the current. Such a field is
shown in Fig. 11, A being the conductor through which flows the
current producing the field. If a second conductor, as B, is brought
into this field the expanding and contracting lines of force cut across
B, and by this cutting induce alternating currents in B.

An application of this principle is found in the static trans-
former. When a coil of wire A, as in Fig. 12, is wound upon an
iron core B, and at another point on this iron core a second coil C
is wound, an alternating current flowing in A sets up alternating
lines of force, which are, by reason of its magnetic conductivity

202 ASSOCIATION OF ENGINEERING SOCIETIES.

being better than that of air, drawn into B. These hnes of force
generate an alternating current in C, hence the dynamo (for the
transformer is a dynamo) has in this instance its armature C sta-
tionary while the magnetism revolves.

It is largely this transformer action which makes the direct-
current motor a failure when operated on alternating currents.
The effect of this action may be seen in Fig. 13. The coil C, which
is a portion of the armature winding, is in the position where, by
its rotation alone, it is generating no electrical pressure, and there-
fore supplying no current to the outside line. In a direct-current
motor, where the magnetic field is constant, this wire is practically
dead at this instant, and the brush bearing upon the two commuta-
tor bars which are connected to the ends of these loops of wire,
notwithstanding that it short-circuits this coil for an instant, causes
no sparking.

With an alternating magnetism, however, the coil is in posi-
tion to act as the secondary of a transformer, and the short circuit
through the brush causes a current flow which produces a spark
when the brush passes onto the succeeding segments of the commu-
tator. This sparking is such as to make continuous operation in
this manner impracticable.

Alternating-current motors, therefore, remained a practical
failure until an entirely new principle of operation was discovered.
This was the principle of the so-called induction motor. The in-
duction motor is a species of alternating-current transformer. It
corresponds to the transformer in having the three elements of (i)
a primary zuinding, into which current is fed from the supply cir-
cuits; (2) an iron circuit, or scries of circuits, in which alternating

ALTERNATING-CURRENT POWER MOTORS.

203

magnetism is set up by the current flowing in the primary winding,
and (3) a secondary zvinding, in which currents are induced as it
cuts the magnetic lines of force produced by the primary winding.
This primary winding corresponds to the field zvinding of the direct-

FiG. 15.

current motor and the secondary windmg to the armature of the
direct-current motor.

The induction motor is built to operate on either the ordinary
alternating current shown in Fig. 5 or on currents of two or more

204

ASSOCIATION OF ENGINEERING SOCIETIES.

phases. This form of motor attained its first practical develop-
ment in this country at the hands of Tesla, who found, after much
experimenting, that commercial results could be secured in such a
motor if currents of two or more phases were used to produce a
so-called rotating magnetic field. He found that he could produce
this rotating magnetic field by having on his motor two or more
entirely independent field windings. By giving these windings
the same relative position in the motor as the different phases of his

x'lG. 17.

supply current bore to each other, he found that he could produce
the eft'ect of a strong magnetic pole revolving around the surface
of his armature at a speed, in revolutions per minute, depending
upon the frequency of alternations of his current. In a motor
such as that shown in Fig. 14, for example, he wound what would
ordinarily be a 12-pole machine in such a manner as to give him
three sets of 4 poles each (thus producing a 4-pole machine), into

ALTERNATING-CURRENT POWf:R MOTORS.

205

which he could introduce three phases of current supply. One
phase, supplying a set of poles AAAA, produced poles the strength
of which followed a periodic wave just as did the alternating sup-
ply. At any one instant such a pole might be positive. As its
strength began to decrease a second phase of current, supplying a
set of poles BBBB, caused a gradually increasing strength of pole
which had the effect of shifting the pole from A to B, and so on.
For such a field winding it was, in course of time, found advantage-
ous to use a form of armature illustrated in Fig. 15. In this arma-
ture the winding of copper conductors consists simply of a large
number of bars completely short-circuited at both ends, with
respect to each other, by a copper ring. The resemblance of this

form of winding to an old-style squirrel-cage gave rise to the
popular name of a squirrel-cage winding. Such an armature
placed in a rotating magnetic field will start from rest with a large
torque, and will quickly run up to a speed slightly less than the
number of alternations of the current supply divided by the num-
ber of poles of the winding. In other words, if the motor in Fig.
14 were supplied with alternating currents of 7200 alternations per
minute the speed of rotation of the armature would be slightly less
than 1800 revolutions per minute, there being four poles of the
winding.

Such a motor supplied with single-phase currents, as for
example Fig. 16, however, will not start from rest. This is due to
the following reasons :

206

ASSOCIATION OF ENGINEERING SOCIETIES.

The currents generated by induction in the armature conduc-
tors when the armature is standing still select such paths of flow
as to produce no turning couple. Some of the currents tend to
produce rotation in one direction, while others tend to produce
rotation in another. They thus nullify each other in so far as turn-
ing moment goes. In the two-phase and three-phase motors, how-
ever, a different condition exists. The currents produced in the
armature by any one set of poles bear the right relation to the
poles of the next phase to afford an effective turning couple, and
therefore the multiphase motors are very effective in starting from
rest. Accordingly it is not surprising that very soon after the
discovery of the induction motor and a reduction to practice of the
principles of generating and transmitting two-phase and three-

no. ig.

phase currents excellent two-phase and three-phase power motors
were placed upon the market. Those manufacturing companies
owning the two-phase and three-phase patents were not slow to
develop a complete system of two- and three-phase power trans-
mission, utilizing induction motors satisfactory to a very high de-
gree.

Great inducement existed, however, to produce a satisfactory
single-phase motor operating along the same general lines. First
of all, a very large percentage of the alternating-current central

ALTERNATING-CURRENT POWER MOTORS. 207

stations in existence made it necessary, if these plants were to sup-
ply alternating-current power motor service, either to develop
single-phase alternating-current power motors or to discard their
old generating apparatus. Further than this, if good single-phase
motors could be produced which would not introduce disturbing

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effects, in so far as lighting service was concerned, a single-phase
system would possess very material advantages over the two-phase
or three-phase system.

Therefore the aim of many investigators has been, even since
the advent of the successful two- and three-phase motors, to de-
velop and offer to power users generally a thoroughly practical

208

ASSOCIATION OF ENGINEERING SOCIETIES.

and commercial single-phase power motor. Such a motor has been
brought out by the Wagner Electric Manufacturing Company, of
St. Louis, and it is of this motor that I desire to speak in detail.
The mechanical construction of the motor is in many respects like
that of the two- and three-phase motors on the market. A field
is built up of iron plates very much like A of Fig. 17, and an

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armature core is also built up from iron plates very much like B of
Fig. 17. The field is w^ound with coils threading through the slots
of the punchings, as shown at C, Fig. 17, so as to produce a mag-
netic pole of intensity varying from a maximum along the radius
XY to zero along the radius XZ. For motors of 60 cycles and in
smaller sizes it is customary to make these field windings 4-pole.

ALTERNATING-CURRENT POWER MOTORS.

209

The armature cores are wound with an ordinary direct-current pro-
gressive winding, connected up to a commutator in exactly the same
fashion as in the direct-current motor winding. The commutator
of this armature is so designed that it may be completely short-cir-
cuited by introducing a short-circuiting circle of copper segments.
When so short-circuited this winding afifords a substitute for the
squirrel-cage form of winding, differing from the squirrel-cage iri

m
so

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teo 200
Fig. 25.

360

that, instead of the currents being left to select paths for them-
selves, they are restricted to flowing in paths afforded by the indi-
vidual coils of the armature winding. The operation of this motor
is based wholly upon the principle that an induction motor with a
completely short-circuited armature will, when up to the running
speed, operate on single-phase current supply in exactly the same
manner -as it operates in a two- or three-phase motor with two-

210 ASSOCIATION OF ENGINEERING SOCIETIES.

and three-phase current supply. In other words, the disadvan-
tage of the single-phase motor, as compared with the two- and
three-phase motors, disappears when up to running speed. There-
fore, in developing a successful single-phase motor, the problem to
be met was the provision of a starting device which would afford
ample starting torque at all speeds between rest and running speed

%2l
30

20

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1^0 900 240 280 320 360

Fig. 26.

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Fig. 27.

2S0 320 369

without excessive consumption of current, and of a mechanical con-
struction equally durable with the rest of the motor. In doing this
the Wagner Company has developed to a high degree of mechanical
and electrical perfection a type of motor equal in all respects, and
superior in several, to the best forms of the direct-current motor.
In effect, this motor starts with the same characteristics of torque
and current consumption as does the ordinary series-wound direct-

ALTERNATING-CURRENT POWER I^IOTORS. 211

current motor, such as is found in all street car equipments, for
example. The armature winding is short-circuited through carbon
brushes bearing upon the commutator surface. The field generates,
by induction, currents in the armature winding, which currents flow
out through the carbon brushes either into an outside resistance or,
where a direct short circuit of the brushes is provided, out through
one brush and back into the armature through the other. By the
shifting of the brushes on the commutator surface these armature
currents are forced to take such positions, relative to the magnetic
poles produced by the field, that a repellent action between these
armature currents and the poles of the fields is efifected and rota-
tion results. In other words, the currents which would l)e ineffec-
tive in an armature construction such as was shown in Fig. 15 are
forced to take such positions that they become equally effective with

4^/(/ 2i>0 320 3eo

the currents produced in the armatures of two- and three-phase
motors. This arrangement of afi^airs, illustrated in Fig. 18, is
employed in bringing the motor up to running speed. When run-
ning speed is attained the brushes are no longer required, and the
armature winding is completely short-circuited, after which the
armature runs purely as does the armature of a two- and three-
phase motor.

In the mechanical development of this form of motor many
novel features have been introduced. The commutator is of the
radial, instead of the horizontal, type. The short-circuiting band
is made up of small copper links, which links, being in turn mounted
upon a short-circuiting ring, are thrown into the annular opening in
the commutator, and by making close contact with each segment
produce a very efifective short-circuiting of the entire armature
15

212 ASSOCIATION OF ENGINEERING SOCIETIES.

winding. In the operation of the motor it is very advantageous to
have this short-circuiting accompHshed either at the running speed
or very sHghtly below. To remove all uncertainty on this score,
the Wagner Company's motors are built with an automatic device
for performing this operation. This device consists of a set of
governor weights acting against a spiral spring. The centrifugal
action of the weights will, at the proper speed, force the short-
circuiting links into the commutator against the action of the spring.
At the same instant, and by the same means, the brushes bearing
upon the commutator are thrown off, and therefore, in the running
condition, the motor runs with much less noise than does the direct-
current motor. (See Fig. 9.) These motors are so designed as to
carry a large percentage of overload without serious consequence.
If this capacity for overload is exceeded this type of motor will

Fig. 29.

come to rest in exactly the same way as will a two- or three-phase
motor under the same conditions. If the overload is temporary
the motor will, without any further attention, run back up to speed,
as in slowing down the brushes are thrown back on the surface of
the commutator by the automatic device, and the motor is again
placed in the starting condition.

In its electrical design this motor has been as highly developed
as in its mechanical features, and the builders claim for it results
practically identical with the best that have been secured with the
two- and three-phase motors. The important characteristics of
such a motor are its starting torque, consumption of current in
starting, consumption of current while running idle without load,
power factor, efificiency and slip. The starting current of this
motor can be varied at will to meet all requirements of the service.
This is accomplished by shifting the brushes upon the commutator

ALTERNATING-CURRENT POWER MOTORS.

213

surface. If large starting torque is essential, the proper placing of
the brushes will produce this, the current consumption bearing
practically a direct ratio to the amount of torque. If a very small
torque only is essential, the starting current can be reduced to a
very small amount. The motors, when they leave the factory, are
so adjusted as to provide sufficient torque to bring up their full
load. The relation of starting torque to starting current is shown
in Fig. 20. The energy required to operate the motor without load
is very small, being practically the same as that required by direct-
current motors. The efficiencies which have been secured in these
motors are practically identical with those secured in the best direct-
current motors. The power factors are as high as those secured

l\Kt

DOUBLE POlC
raSE. BLOCK,

STARTiMC PGSiTlOW

OOUBi.£ POLE

OOUBLE THSOW

SWITCH

PUWNIWC POSITION

OILlClUCE LEIEL

Fig. 30.

in two- and three-phase motors, and the slip is very small indeed.
By this latter factor of slip is meant the decrease in speed between
no load and full load. It may be said that this is about the same
as in a good shunt- wound direct-ciUTcnt motor. In Figs. 21 to 28
I have shown the results of a test made by students of the Univer-
sity of Nebraska, during the spring of 1898, upon a 5-horse power
motor. These tests were made under the direct supervision of
Professor R. B. Owens. One set of tests was the measurement of
the various electrical factors with ditferent applied electrical pres-
sures at the terminals of the motor. In other words, the motor, as
sent out by the builders, was designed to operate on a pressure
of 104 volts and on 60 cycles. Tests were made with a variation
of this voltage in steps between 70 and 120. The effect of these

214

ASSOCIATION OF ENGINEERING SOCIETIES.

various voltages upon the several factors are very nicely illustrated
in Figs. 21 to 24, inclusive. The judiciousness of the ratings given
by the builders is, I think, very clearly brought out in these curves.
A particularly noticeable feature is the small percentage of slip at
the rated capacity of the motor, — namely, 3 per cent.

Another set of tests was made by these gentlemen for the
determination of the exact magnetic actions going on in the motor.
In other words, they attempted to determine, under all conditions of
load, as well as when standing idle, the exact form of magnetic field
produced by their single-phase sign-wave current supply. To de-
termine these measurements they introduced exploring coils in the
slots of the field punchings. Each of these exploring coils embraced

OUTSIDE

Fig. 32

one-fourth of the slots of the entire field punching, corresponding in
that way to the exact breadth of the polar winding of the motor.
These exploring coils were introduced progressively around the
frame in such a way that the first one enclosed the entire winding of
one pole, the next one eight-ninths of the winding of one pole and
one-ninth of the winding of the next pole ; the third one enclosed
seven-ninths of the winding of one pole, and two-ninths the winding
of the next, etc., progressively, until a point was reached where half
of one pole and half of the next pole were enclosed. By the proper
introduction of measuring apparatus the experimentors could
accurately determine at any one instant the magnetic strength in
the section of the field embraced bv each coil.

ALTERNATING-CURRENT POWER MOTORS. 215

Therefore, plotting these instantaneous resuhs with respect to
time, they could determine the exact form of a wave and its net
numerical value all around the interior surface of the field punch-
ings. In Fig. 25 the results of their tests are shown with the motor
standing still. The result here is just what might have been ex-
pected,— namely, that in this condition of affairs the field is a pulsat-
ing one, and decreases in magnitude at any instant as we progress
around the circumference of the field from the central radius of
each pole. In Fig. 26 is shown the reactive effect of the armature
upon the strength of the field immediately in the center of each
pole-winding between the limits of no load, half load and full load
in one direction. The displacement seems to correspond in per-
centage to the percentage of slip. In Fig. 27 are plotted the re-
active results on the magnetic field, caused by the rotation and the
current of the armature winding. A close study of these curves,
as compared with the curves of Fig. 25, reveals the fact that the
armature reactions of the motor when up to speed are such as to
change entirely the character of the magnetic field, actually produc-
ing as perfect a rotating magnetic field as is created by a multiphase
current supply. In Fig. 28 is shown the reactive effect of the
armature upon that portion of the field embraced in the exploring
coil, which gives a horizontal line in Fig. 25. Here Curve i shows
that the resultant magnetism enclosed by this exploring coil is zero
when the motor is at rest. Curve 2 shows the condition of affairs
with the motor running in one direction. Curve 4 gives the corre-
sponding result with the motor running in the other direction.
Curve 3 shows the displacement of 4, due to load of the motor.
These various magnetic curves are worthy of much closer study
than can be given them within the limits of this paper.

Another test made by the university students was to determine
the effect of continuous load upon the motor ; in other words, to
compare the electrical conditions of the motor operating cold and
liot. These results are shown in Fig. 29, and disclose the fact that
the motor is more efficient and operates with better results in every
respect, except slight increase in the percentage of slip, when hot
than when cold. In the winding of these motors it is possible for
the builders to secure a variety of results. ]n other words, where a
very large starting torque is required an auxiliary connection can
be made, the effect of which is to rate up the motor in capacity.
The builders term this a loop connection, and for this connection
they provide a third terminal upon the terminal board. If the cir-
cuit is connected to this terminal and the common terminal for
starting, 50 per cent., 75 per cent, and in extreme cases 100 per

2i6 ASSOCIATION OF ENGINEERING SOCIETIES.

cent, overload may be brought up to running speed. When up
to running speed connections are changed by means of a throw
over switch in the supply circuit, so that the current is supplied to
the normal winding of the field. The diagram for connections in
such circumstances is shown in Fig. 30. Where the starting torque
required is normal, the diagram for connections is as shown in Fig.
31. If it is desired to limit the starting current for the purpose of
avoiding line drop of pressure, the builders furnish a small trans-
former for reducing the pressure applied to the motor terminals.
The connections under such circumstances are as shown in Fig. 32,
and the result accomplished is the cutting off of that part of the
torque and current curves of Fig. 20 above the 150 per cent. line.
The extreme simplicity of the motor arises from the fact that it can
be connected upon the same circuit with incandescent lamps, and
that it operates without any disadvantageous effects on incandescent
circuits. Furthermore, operating on a low tension, there is no
danger from accidental contact. If it is desired, however, to oper-
ate on higher voltages, windings will be provided to correspond.
The manufacturers have designed alternating-current motors of this
character up to and including 20 horse power capacity for 60
cycles, and 15 horse power for 133 cycles. It is understood that
larger sizes are to be brought out in the near future. It may be
said in passing, however, that practically the limit of requirement
for ordinary commercial power purposes is 50 horse power capacity.
The limit of adaptability of this motor to various descriptions of
power work is set by the necessary frequency of starting, as above
explained. The motor cannot be continuously operated upon the
commutator, and so long as the starting is of infrequent character
satisfactory results can be guaranteed. For ordinary running ser-
vice, where starting but a few times a day is necessary, the life of
the commutator is indefinite, and motors are running in the shops
of the Wagner Company, which have been in service for two years-
or more, the commutators of which have never received more than
a verv limited amount of attention.

PATENTS AND MONOPOLY. 217

PATENTS AND MONOPOI^Y.

By John Richards, Member Technical Society of the Pacific Coast.

[Read before the Society, November 3, 1899.*]

Before entering upon the main part of the subject to be pre-
sented, and in order to define the limits of the paper, I will explain
that there is no intention to sustain or to condemn the policy of
granting patents for inventions. The equities and conditions that
surround this phase of the subject, such as that occult faculty
recognized in law, the inventive faculty, and the inherent rights
arising therefrom, would lead into long and profitless discussion.

Twenty-eight years ago I wrote a pamphlet, much more exten- •
sive than the present paper, to contend that inventions in the useful
arts should not become the property of individuals when such inven-
tions or discoveries were deducible from common premises, the
results of science and acquired skill, and that priority in inventions
consisted generally in the discovery of wants.

Such speculations, interesting as they may be to follow out, are
of no practical value in the face of the fact that nearly all civilized
countries, Holland excepted, have patent laws or systems of grant-
ing an exclusive use of new inventions. It is not, therefore, a
theory we have to consider, but a condition.

While the system of granting patents for inventions has re-
mained measurably the same for a quarter of a century past, the
industrial interests affected thereby have been greatly changed and
centralized, establishing, or tending to establish, a new relation of
personal rights in invention. This is the principal theme of the
present paper, and is in every way, I think, a suitable subject to be
brought before this Society, which alone on this coast is in position
to discuss a problem of so technical a nature as the relations between
inventions and industry, and in how far the best relation can be
established Ijv the patent laws and the methods of procedure in the
bureau.

In the American Review of Reviezvs for June, 1899, in the
editorial notes, under the head of "The Rights of ^Monopoly," there
appeared the following remark :

The Government Patent Office every day grants control over certain
inventions with the avowed object of promoting for a term of years a strict
monopoly. If, in some field of industry not dependent upon the protec-

♦Manuscript received November 15, 1899. — Secretary, Ass'n of Eng. Socs.

2i8 ASSOCIATION OF ENGINEERING SOCIETIES.

tidn ot the patent laws, a monopoly should arise by reason of the fact that
a single individual or firm or corporation had come into control of the
entire production of a given article, it would not follow necessarily that
there was any greater propriety in this particular monopoly than in those
especially fostered by the Government under its patent laws.

It is a curious conception that places patents for inventions in
the category of monopoHes. There is scarcely even analogy
between a patent and what is commonly understood by monopoly.
The inventor must, before he enters upon an exclusive use of his
own discovery, prepare it for public use at the end of a term of
years, averaging fifteen, by means of carefully executed specifica-
tions and drawings, which, if faulty, incomplete or insufiicient to
disclose fully his invention, invalidate his right of exclusive use.
This does not appear like monopoly.

In its nature a patent is simply a compact between an inventor
and the public, whereby he is for a limited time permitted on certain
conditions to use exclusively what is already his own by natural
right, on condition of disclosure and dedication to public use at the
end of a term scarcely long enough to develop his invention; he
paying all the fees for registry and conveyance to the public and
something more than this, because at this time in this country inven-
tors have overpaid such expenses to- the extent of nearly four
millions of dollars, now lying in the National Treasury.

In the case of authors and their writings the terms are more
liberal. The period of personal right is longer, is renewable and is
more carefully protected by law. The fees of registry are merely
nominal, and encouragement is in every way extended, as it no
doubt shovild be, on grounds of expediency as Avell as of equity and
right.

The history of patents for inventions fully discloses their
nature. The various patent systems of the world may all be said
to rest upon a modification of an old English law called the Statute
of Monopolies, which, previous to 1633, had led to various abuses
by special grants or privileges, called "patents," that were sold or
bestowed by the crown upon favorites. Such grants, then consid-
ered "acts of grace," were given for an exclusive right to make or
sell special commodities, even the common necessaries of life, such
as salt, which was once the subject of a patent. This was monopoly.

The abuses under this law, the Statute of Monopolies, became
so intolerable that it was repealed in 1633, c>^cept in so far as inven-
tions were concerned, and was in effect superseded by the present
statute, which confines personal monopoly to "inventions," or what
was "new in the realm." so that no citizen should be al)ridged in any
right he had previously enjoyed. Section 6, on which the patent
laws rest, reads as follows :

PATENTS AND MONOPOLY. 219

Provided that any declaration before mentioned'^' shall not extend to
any letters patent and grants of privilege for the term of fourteen years
or under hereafter to be made of the sole working or making of any man-
ner of new manufactures within this realm to the true and first inventor
of such manufactures, which others at the time of making such letters
patent and grants shall not use, so as also they be not contrary to the law
nor mischievous to the State, by raising prices of commodities at home,
or hurt of trade, or generally inconvenient, the said fourteen years to be
accounted from the date of the first letters patent or grants of such privilege
hereafter to be made, but that the same shall be of such force as they should
be if this act had never been made, and of none other.

As before remarked, this old law has stood for 266 years as the
foundation on Avhich patent laws are founded in all countries where
such rights are conveyed to inventors. It was obvious to Parlia-
ment that no monopoly could exist in respect to inventions, and
these were accordingly excluded in the repeal of the old law.

Sir Edward Coke, the great English jurist, defining the scope
of the revised statute, said :

An illegal monopoly is a grant or allowance from the king by his grant,
commission or otherwise to any person or persons, bodies politic or corpor-
ate, of or for the sole bringing in, selling, making, working or using anything
whereby any person or persons, bodies politic or corporate are sought to be
re-'trained of any freedom or liberty that they had before, or hindered in
their lawful trade.

Numerous authorities could be given showing that not only
are patent grants for invention free from the feature commonly
understood as monopoly, and are no restraint upon the rights of the
commonwealth or of persons, but also that, notwithstanding these
clear facts of history, the old original concept of a monopoly patent
has lingered for more than two centuries, as is seen in the quotation
given at the beginning of this article and in others to be hereafter
noted. As a matter of fact, patents for inventions, since 1633,
instead of constittiting a monopoly, have been a limitation of a
natural right that inheres in the person, the ecjuity of such limita-
tion resting on an assumed probability that within a certain period
of time the public would by other means become possessed of the
same discovery.

Nothing is confirmed by a patent grant. It is simply a warrant
of privilege to appeal to the courts for the protection of a personally
created new property, and even this right, as before pointed out, is
made conditional on the fact of an originality which the inventor
must himself, at his own expense, establish, in most cases against
prejudice and nice discriminations of a technical nattirc scarcely
definable in set laws.

^Referring to the act repealing the Law of ]\Ionopolies.

220 ASSOCIATION OF ENGINEERING SOCIETIES.

The patent laws of the United States were instituted i6o years
later than those of England, and, while differing in many pro-
visions from the British system, recognize fully the principle, laid
down in the repeal of the Statute of Monopolies, that no grant
should bar from use or enjoyment any knowledge or right held by
i-.ny one before the discovery or invention patented.

One distinction from the British system is in the meaning
attached to the name "inventor."

In the quotation from Chief Justice Coke it will be noticed that
he includes, with discovery, "sole bringing in." This yet consti-
tutes "invention" in Great Britain and some other countries. In
fact, the term, etymolbgically considered, means to "bring in," being
derived from the Latin in and venire, to come in, or bring in, and
applies especially to the introducer of an invention or to "communi-
cations from abroad" ; but there are provided reasonable safeguards
to prevent abuse of this privilege.

In the United States the limitations are more strictly drawn.
Inventions are made purely personal, without power of delegation
from a living inventor. He alone can procure a patent, and should
error be made by false or mistaken statement, so as to abridge the
rights of an earlier inventor, the statute provides means of correct-
ing such mistake and confirming the grant to the actual first
mventor, thus carefully protecting not only the public but each
individual against the infraction of any privilege previously
enjoyed.

The Constitution of the United States confers upon Congress
the power to grant, for a limited time, to authors and inventors, an
exclusive right to their writings and discoveries for the promotion
of science and the useful arts. This took form at the end of the
last centur}^ by the enactment of a patent law which in 1870 was
revised and put upon a more permanent basis, which has lasted
without material change to the present time, and which, with an
exception to be hereafter mentioned, has operated in a satisfactory
manner.

This law, under the circumstances of our time, furnishes almost
the sole means whereby a small industry can be started and carried
en, notwithstanding that for fifty years or more patented inventions
were a common basis for extensive industrial organizations.

In manufactures so founded individual skill was the prominent
and often the main factor. Men without capital were able to
acquire and control interests in various industrial enterprises,
especially such as grew out of small individual beginnings founded
on patents for inventions. Now circumstances have changed. In

PATENTS AND MONOPOLY. 221

the enormous activities of modern industrial development individu-
ality is practically eliminated, and various means of monopoly have
arisen.

Such means consist in the control of legal and other employed
skill ; the purchase of material and supplies at a reduced rate ; reduc-
tion in the cost of transportation ; borrowing" money at low rates of
interest; reducing the expenses of management; saving in the
expenses of advertising; raising the price of the product, with many
ether advantageous conditions which go to make up monopoly and
occupy the former place of patented inventions.

In this manner there has arisen a conflict of interests and a
jealousy of patented inventions that will no doubt in the near future
lead to attempts at modifying the patent laws, or to a new construc-
tion of them by the courts that will impair the rights of inventors.
Even at this time we have a decision in which by an unparalleled
dictum a Federal judge has set aside an important and generally
recognized patent* by deciding a ivant of invention. Such an
assumption was contradicted by facts, testimony and the opinions
of those skilled in the art. If one patent can be destroyed in this
manner, why may not any other meet the same fate The judge
of a court may from facts decide questions of infringement and of
novelty, because these rest upon fact, and skilled aid can be called
in to clear up history and technical features ; but when a court
assumes to determine the degree of invention in a case, this leads
into a field that has no limit and to the exercise of functions that
belong to the skilled officers of the Patent Office. An officer of the
law, not skilled in the arts, is not competent to set up a measure of
invention.

The whole world seems engaged in a wild race for gain. The
commercial incentive becomes stronger each year, and the frantic
attempts to adapt laws to the neW circumstances show the slow
and unwieldy nature of legislation and the difficulty of framing
"rules of action" for new arts and interests. In one decade, or
even in half that time, may arise discoveries and economic changes
that greatly afTect the social relations of people ; and this rapid and
revolutionary march of centralization and the altered social condi-
tions produced thereby are the primal causes of unrest and the many
turbulent social problems that are at this time forcing themselves on
the attention of thinking people.

The effect of an attack upon the patent system, and the results
that would follow in the social, economic and industrial interests of

*U. S. Circuit Court, District of Northern California, Johnson vs.
Woodbury, No. 11,934, i899-

222 ASSOCIATION OF ENGINEERING SOCIETIES.

the country, are matters of serious import. Even now a small
manufacture of any commodity of common use is impossible unless
the product or process is protected by a patent. Hence the incen-
tive to disparage and impair such protection by classing it with
"monopoly."

There are now enrolled in Congress no less than seventy bills
that would, if enacted, affect the patent laws or procedure. Some
of these bills are for useful purposes, and more of them are not.
Some of them have their initiative in personal objects, and many
indicate a want of information respecting the nature and equities
involved in patent grants.

There is no sufficient understanding of patent matters in Con-
gress any more than there is among the people ; besides, there is the
impediment to the consideration of such bills that they are of a
national character, and lack the usual incentives to promote their
consideration. So the subject is neglected, while the Patent Office,
with an enormous surplus fund lying in the National Treasury, is
without even the required room and facilities for transacting its
business.

Fortunately, however, an association of leading members of
the bar and patent attorneys at Washington, many of whom have
held executive positions in the bureau, give consideration to new
hills affecting patent laws and procedure. The Patent Law Asso-
ciation considers the various proposed changes, publishes digests of
new bills and may be said to control legislation to the extent of
preventing the enactment of new laws and rules that would lead to
bad results. It also promotes what tends to improvement of thp
system.

To illustrate the methods of this organization, the Patent Lazv
Association in November, 1898, published a bulletin containing a
digest and review of pending Congressional bills, and, in respect to
two aft'ecting the trade-mark law (H. R. No. 2807 and H. R. No.
3128), has this to say :

Of the many lawyers to whom these bills were presented for criticism
not one indorsed any of them. The singular lack of precision, joined with
the comprehensive scheme of the undertaking and the insistence with which
they were urged, makes these bills peculiar examples of what must be met
by all associations and individuals who have at heart the real advantage
of the law and the good of all.

Two characteristics of the American Patent Bureau are note-
worthy,— the purity of its administration and its paternalism.

Throuf;hout the century of its existence there has never arisen
any serious case where the integrity and good faith of the officers

PATENTS AND .MONOPOLY. 223

have been called in question. They are in a great measure free
from the baneful intiuences of political preference, and have main-
lained a spirit of independent action strange to find among so much
of an opposite character. The popular confidence thus gained has
rendered possible the present "paternal" features of procedure.

By paternalism is meant the elaborate system of examination
performed by subordinate officers clothed with the power of witness,
counsel and judge. A "triple function" it may be called. Each
primary examiner exercises all of the functions of the bureau up
to appeal ; adducing testimony as to the novelty of inventions, the
relation and liearing of such testimony and then passes judicially
upon his own findings. This work, if advisory, or if it resulted in
"objection," would be as logical as it is useful, but it is not con-
sistent with the fact that there is no corresponding power to "con-
firm." It is a proceeding that acts in one way only.

An applicant has to assume the whole responsibility when his
application is "allowed." Infraction of his patent gives him the
privilege of complaint in the courts, but nothing more. If his
case is rejected he has no standing or privilege, no matter what the
real facts may be.

During procedure he is put in the position of a humble peti-
tioner praying for the allowance of his claims, asking for all he
can get and taking what in the examiner's opinion he should have.
This constitutes a paternal system, and is responsible for the widely
prevalent opinion that an "allowance" of a patent is at the same
time a confirmation of its validity.

This paternal system gives rise to the existence of incompetent
attorneys and to faulty methods of procedure, because both inven-
tors and their agents depend on the office and commonly present
their cases in an imperfect or overdrawn form, based on the rule,
"Claim everything, and get what you can." Out of this form of
procedure arises the common opinion that a patent is an "act of
grace," — a favor and privilege emanating in and conveyed by the
Government.

This conception of patents for inventions furnishes logical
grovmds for the charge of monopoly. It also presents a vulnerable
point of attack by those whose interest it is to destroy property in
mvention. This mode of procedure is not necessar}^ as is proved
by the fact that repeated and invalid patents are as common in this
country as those where the applicant and his attorney assume the
responsibility of novelty and the governments deal only with form.

Competent attorneys who prepare here applications for patents
in foreign countries will understand this peculiar method of pro-

224 ASSOCIATION OF ENGINEERING SOCIETIES.

cedure in domestic cases, and are governed accordingly. For the
American office they will draw a large number of ambiguous claims,
approaching the novel features of the invention from various sides,
introduce technical language not capable of being understood in a
popular way and in amendments proceed to hair-splitting distinc-
tions.

Specilications for other countries are drawn with the essential
features of the invention expressed usually in a single claim and
m plain terms, describing the thing or part invented as nearly as the
applicant and his attorney can determine this point, and usually in
'i way to secure a sound patent when there are grounds to admit of
such.

It is not contended that the methods of procedure in this coun-
try can at once be altered. We have drifted into a system that per-
mits almost any one to become a patent attorney, depending on the
bureau to do the work. To change this and to make the applicant
responsible in procedure, as he is in fact, would eliminate the
paternal feature and at the same time remove a false conception of
the nature of a patent.

Referring further to the relation between patents and monop-
oly, in September of the present year there assembled at Chicago a
congress of men, eminent in economic matters, to deliberate on
"trusts" or the monopoly exercised by these combinations. One
of the delegates to this conference. Professor Jenks, read a paper
before that body in which, with other suggested inquiries or prob-
lems, was one as to "whether the patent laws should not be so
changed as to prevent the right of monopoly accruing to the
patentee," thus placing inventions in the same category with com-
mercial monopolies.

Mr. Bourke Cockran, of New York, in an address before the
same body, said : "Now, there are three ways in which the Govern-
ment interferes in the trade of the individual in this country ; one is
by patent laws."

He naipes patents first as a cheap kind of monopoly, and then
goes on to recommend the suppression of monopoly by the remedy
of "publicity."

How would it do, let one ask in amazement at this statement, to
issue charters in the same manner as patents on inventions? For
example, (i) the term to last seventeen years; (2) the apphcant to
file at the beginning a complete exposition of his business for public
use at the end of this term ; (3) to make the privilege contingent on
there being no interference with rights previously enjoyed by
others; (4) to declare in a publicly printed document the nature,

PATENTS AND MONOPOLY. 225

conditions and limitations of the grant and sell the same for five
cents a copy.

This, it seems, should satisfy Mr. Cockran's desire. What he
has in mind is, no doubt, to throw around all kinds of chartered
privileges some such restrictions as are now applied to patents for
inventions. If that were done the monopoly would be eliminated,
as it is by the spirit, letter and intent of patent laws as they have
existed since 1633.

Since the foregoing matter was prepared the Assistant Com-
missioner of Patents in this country, Mr. A. P. Greeley, has pub-
lished a volume entitled "Foreign Patent and Trade-Mark Laws."
In this volume are various explanations and comments on the dif-
ferences in systems and procedure. On pages 18 and 19 the fol-
lowing will be found :

The idea that the grant of a patent for a new invention is in some way
in derogation of the rights of others, and that it is for the interest of the
public that the invention should be made free to any one to use at as early
a date as possible, is not yet wholly overcome, even in the United States.
'^ * * In the United States, while a patent once granted is not liable
to forfeiture for any cause, the disposition to consider that the public inter-
est demands that every technicality of the law should be taken advantage of
against the patentee, particularly in the construction placed on the claims
of his patent, has, it is to be feared, too often resulted in depriving a meri-
torious inventor of the protection to which he was justly entitled.

On pages 32 and 33 the following will be found :

The countries which can be said to have patent offices properly equipped
to make anything like an exhaustive examination on the question of novelty
are, besides the United .States, Austria, Canada, Denmark, Germany, Japan,
Norway, Russia, Sweden and Switzerland. In all of these except Switzer-
land a patent is refused if the invention is found to be not patentably new.
Under the Swiss law, the applicant is informed of the result of the examina-
tion and given an opportunity to amend, if necessary; but if he does not do
so, or insists that a patent issue, even though the invention is shown to be
old, the patent cannot be refused. A similar plan is under consideration in
Great Britain, and is likely to be adopted.

On page 37 the following, including a footnote, appears :

And while patents granted after preliminary examinations are very often
submitted to experts for opinion as to their validity, especially if suit for in-
fringement is to be brought on them, they are recognized, generally, as
prima facie valid.

While this is true of all other countries in which the preliminary exam-
ination system prevails, and was true of the United States up to 1879, it can-
not, unfortunately, be said to be strictly true at present of the United States.

Editors reprinting articles from this journal are requested to credit both
the Journal and the Society before which such articles were read.

As

SOCIATION

OF

Engineering Societies.

Organized. 1881.

Vol. XXIII. DECEMBER, 1899. No. 6.

This Association is not responsible for the subject-matter contributed by any Society or
for the statements or opinions of members of the Societies.

THE INFLUENCE OF MECHANICAL DRAFT UPON THE
ULTIMATE EFFICIENCY OF STEAM BOILERS.

By Walter B. Snow, M.E.

[Read before the Boston Society of Civil Engineers, October i8, 1899.*]

A DISCUSSION of the influence of mechanical draft upon the
ultimate efficiency of steam boilers may very properly be introduced
by a word regarding the apparatus, and a brief description of the
methods employed in its production. In its generally accepted
form the apparatus consists of a fan blower inclosed in a case and
provided with the necessary means for its operation.

The fan -Avheel itself consists of a number of radial blades
carried upon T steel arms cast into the hub. Side plates bind the
blades together, and provide two inlets concentric with the shaft;
one upon each side of the wheel. The air enters through these
inlets and is by the action of centrifugal force delivered tangentially
at the tips of the blades, which conform to the outer circumference
of the wheel. The air, thus discharged, is, by means of a surround-
ing case, conducted to an outlet in its circumference.

The volume delivered by a fan is proportional to its speed,
while the pressure created varies as the square of the speed, and the
power required as the cube of the speed.

Mechanical draft may be applied under either of two general
methods, the plenum and the vacuum. Which is to be employed
must depend upon the circumstances, for it cannot be asserted that
either is unqualifiedly superior under all conditions. As ordinarily
applied, under the plenum or forced draft method, the air is forced
into the closed ashpit under pressure, and thence finds its escape
through the fuel on the grates above. Its success depends largely
upon the manner of introduction of the air to the ashpits. For

*Manuscript received November 23, 1899. — Secretary, Ass'n of Eng. Socs.
16

228

ASSOCIATION OF ENGINEERING SOCIETIES.

this purpose a special form of damper is desirable, as shown in
Figs. I and 2.

fe

tn

MECHANICAL DRAFT.

229

In a forced draft installation, as illustrated in Fig. i, the fan
may be so designed that the air is discharged into an underground

Fig. 2. Ashpit Damper in Bridge Wall.
brick duct, extending along the front of the boilers, whence it passes
through branch duct's to the individual dampers in the ashpits.

F'iG. 3. Forced Draft Plant with Hollow Bridge Wall.
One of these, with its means of operation, is very clearly shown at
the right of the cut. Such an arrangement is readily applicable to
a boiler plant already installed.

230

ASSOCIATION OF ENGINEERING SOCIETIES.

In a new plant, however, the bridge wall may be left hollow
and utilized as an air duct, a damper, of the form shown in P ig. 2,
being employed and operated from the front by means of the
notched handle bar. The elifect of both forms of damper is to
spread the air evenly over the entire bottom of the ashpit, whence

Fig. 4. Induced Draft Plant with Single Fan.

it rises in even volume at low velocity. A plant arranged on the
forced draft principle, designed to discharge through a hollow
bridge wall, is clearly shown in Fig. 3.

Under the vacuum or induced method, the fan is introduced
as a direct substitute for the chimney, creating a vacuum in the
furnace and drawing therefrom the gases generated in the process

MECHANICAL DRAFT.

231

of combustion. As the draft is thus rendered positive and practi-
cahy independent of all conditions, except the speed of the fan, it
is necessary to provide only a short outlet pipe to carry the gases
to a sufficient height to permit of their harmless discharge to the
atmosphere.

In practice, the capacity of an induced draft fan must vary with
the temperature of the gases it is designed to handle. Therefore
the density, which varies inversely as the absolute temperature,
should enter as a factor in all such calculations.

Various arrangements of induced draft are usually possible
V ith an ordinary boiler plant. As a rule, the simplest arrangement

Fig. 5. Induced Draft Plant with Duplex Fan.

consists in placing the fan or fans immediately above the boilers,
leading the smoke flue directly to the fan inlet connection, and dis-
charging the gases upward through a short pipe extending just
above the boiler house roof.

The arrangement of a single fan after this manner is shown in
Fig. 4, while a duplex induced draft plant, having two fans, each
of sufficient capacity to produce the required draft for the entire
battery of boilers, is presented in Fig. 5. In both instances the fans
are provided with direct-connected engines having water-cooled
journals.

The ultimate efficiency of a steam boiler is dependent upon
three principal factors :

232

ASSOCIATION OF ENGINEERING SOCIETIES.

First. The primary cost of the entire plant and the fixed
charges thereon.

Second. The quantitative efficiency of the plant as a means
of burning the fuel supplied, and transferring its heat to the water
evaporated.

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lOOO 2.000

Horse Power

Fig. 6. Comparative Cost of Chimney and Mechanical Draft.

Third. The operating expense including the fuel.

In addition there are always distinct advantages or disad-
vantages which, while of marked importance, can be measured only
qualitatively in their relation to the superiority of any given ar-
rangement or appliance.

In so far as mechanical draft has a direct influence on any of
these factors it is the purpose to consider here its ultimate effect
upon the efficiency of the steam boiler plant to which it may be
applied. Naturally, the question of primary cost first enters into

3000

MECHANICAL DRAFT. 233

the consideration, and secondly, that of maintenance and operation,
Vvhile all three of these items are to be viewed in the light of the
efficiency secured. In the matter of first cost comparison is funda-
mentally made between the cost of a chimney and that of a me-
chanical draft plant, which may be introduced as a substitute.

In the accompanying- curves, Fig. 6, are presented the relative
costs of chimneys and of equivalent mechanical draft equipments
in a number of boiler plants widely different in character and rated
capacity. In certain of these the cost of the existing chimney is
known, and that of the complete mechanical draft plant is esti-
mated, while in others the cost of the mechanical draft installation
is determined from the contract price, and the expense of a chimney
to produce equivalent results is calculated. Costs are shown for
both single, forced and induced engine-driven fans, and for duplex
engine-driven plants in which either fan may serve as a relay. An
apparatus of this latter type is evidently most complete, and is
necessarily the most expensive. It finds its greatest use where
economizers are employed.

An average for the costs for these nine representative plants
shows the total expense for installing a forced draft plant to be only
18. X per cent., that of a single induced fan and accessories 26.7 per
cent., and that of a complete duplex induced draft plant 42 per cent,
of that of a chimney. In each case a short steel plate stack is
included.

In other words, if a chimney be estimated to cost $10,000,
there could be saved, on a basis of these averages, the respective
amounts of $8130, $7330 or $5800 in the first cost, according to
which system of mechanical draft is substituted.

For a good steam boiler plant it is fair to assume the following
as average fixed charges:

Interest , 5 per cent.

Depreciation and repairs 4^ "

Insurance and taxes V/z "

Total II per cent.

Experience has shown that these figures also hold good for a
well-designed mechanical draft apparatus, and are therefore ac-
cepted here. On the other hand the fixed charges on a chimney
may be fairly assumed as, —

Interest S per cent.

Depreciation and repairs i ^ "

Insurance and taxes ij^ "

Total 8 per cent.

234 ASSOCIATION OF ENGINEERING SOCIETIES.

COMPARISON OF COSTS AND FIXED CHARGES.

First cost. Annual fixed charges.

Method of draft production. Amount. Ratio. Amount. Ratio.

Chimney $10,000.00 $1.00 $800.00 $1.00

Induced draft plant (2 fans) 4,200.00 .42 462.00 .58

Induced draft plant ( i fan) 2,670.00 .267 294.00 .37

Forced draft plant (i fan) 1,870.00 .187 206.00 .26

The fact that the mechanical draft apparatus can usually be
placed overhead or on top of the boilers where it occupies no valu-
able space, and that the space otherwise occupied bv the chimney is
at the same time rendered available, makes possible a further
saving which is necessarily dependent upon the land values.

Fig. 7. Showing Smoke Pipe to Right of Chimney.

Within city limits it may readily amount to $1000 in a plant of a
thousand horse power.

The relative proportions of a brick chimnev and of the smoke
pipe required when mechanical draft is introduced are forcibly
shown in the accompanying illustrations, Figs. 7 and 8. The
removal of the boilers to a position too far distant from the chimney
to permit of its longer fulfilling its office naturally presented an
excellent opportunity for the substitution of an induced draft fan,
and the subsequent removal of the chimney. The present stack or
smoke pipe, barely visible in Fig. 8, extends only 31 feet above the
ground.

MECHANICAL DRAFT.

235

A concrete case illustrating the possibilities of mechanical
draft is presented in the accompanying drawings, Figs. 9 and 10.
These show a plant of 2400 horse power of modern water-tube
boilers, 12 in number, set in pairs and equipped with economizers.
The left-hand drawing- indicates the location of the chimney 9 feet
in internal diameter by 180 feet high, designed to furnish the neces-
sary draft. To the right is the same plant with a complete duplex
induced draft apparatus substituted for the chimney and placed
above the economizer connections. Each of the two fans is driven
by a special engine, direct-connected to the fan shaft, and each is
capable of producing draft for the entire plant. A short steel plate

Fig. 8. Showing Smoke Pipe to Right of and Below Flag.

stack unites the two fan outlets and discharges the gases just above
the boiler house roof. All of the room necessary for the chimney
is saved, and no valuable space is required for the fans.

COST OF BOILER PLANT WITH CHIMNEY.

12 boilers $37,000.00

2 economizers 10,500.00

Boiler and economizer settings and by-passes 9,000.00

Automatic damper regulators and dampers 400.00

Chimneys, including foundations 10,700. oo^

Boiler house 11,500.00

Total $79,100.00

236 ASSOCIATION OF ENGINEERING SOCIETIES.

rp:lative costs.
Chimney Draft.

Cost of chimney $10,700.00

Cost of damper regulators and dampers 400.00

$11,100.00
Mechanical Draft.

Cost of mechanical draft plant complete 4,700.00

Saving by using mechanical draft 6,400.00

$11,100.00

Fig. 9. 2400 H. P. Boiler Plant Operated Fig. 10. 2400 H. P. Boiler Plant Operated
BY Chimney Draft. by Mechanical Draft.

The costs of the chimney and the mechanical draft apparatus,
which are also indicated, show a saving in first cost of $6400 as the
result of using the mechanical draft method.

The intensity of draft produced by a fan and the readiness and
economy with which it may be secured make it a simple matter to
maintain a combustion rate higher than that ordinarily obtaijied
with a chimney.

The accompanying table, wdiich presents the various pressures,
expressed in pounds per square foot, experimentally determined
by Professor Gale, for a certain stationary boiler, clearly indicates

MECHANICAL DRAFT. 237

that nearly all of the draft is required to overcome resistances inci-
dent to the maintenance of a higher rate. Boilers have naturally
been proportioned to meet these conditions, but it is manifest that,
by changes in design, or by the introduction of heat-abstractors,
they may, under the influence of mechanical draft, be readily oper-
ated at considerably above their original ratings, with substantially
the same efficiency. As a result it is possible to' obtain a given out-
put with a plant of less size and first cost than is possible with a
chimney. This is particularly true where the steam consumption is
liable to sudden fluctuations for comparatively short periods,

FURNACE PRESSURES.

Required to produc: entrance velocity (3.6 feet per second) 0.013

Required to overcome resistance of fire grate o.gi

Required to overcome resistance of combustion chamber and boiler

tubes 1.23

Required to overcome resistance in horizontal flue 0.06

Required to produce discharge velocity (11. 2 feet per second) 0.085

Total effective draft pressure 2.298

Back pressure due to friction in stack 0.19

Total static pressure produced by chimney 2.488

The typical boiler plant already presented will serve as an
■excellent illustration. Suppose it is determined to omit two of the
twelve boilers, say one from each pair at the end farthest from the
•economizers, and to force the remaining boilers up to the original
rating, which can be easily done by mechanical means, as a sub-
stitute for the chimney. This will decrease the rating to 2000
liorse power, or by i6| per cent. The volume of air required per
pound of coal, with the higher combustion rate, deeper fires and
m.echanical draft under automatic control, will be somewhat less
than that with the chimney, while if the economizers remain the
■same, iheir capacity relative to the heating surface of the boilers
will be greater, so that the ultimate waste by heat in the escaping
^ases will certainly not be increased.

RELATIVE COSTS.

2400 Nominal Horse Potver Plant, with Chimney Draft.

12 boilers $37,000.00

2 economizers 10,500.00

Boiler and economizer settings and by-passes 9,000.00

Automatic damper regulators and dampers 400.00

Chimney, including foundations 10,700.00

Boiler house 1 1,500.00

$79,100.00

238 ASSOCIATION OF ENGINEERING SOCIETIES.

2000 Nominal Horse Poiver Plant, zvith Mechanical Draft.

10 boilers $30,833.oa

2 economizers 10,500.00

Boiler and economizer settings and by-passes 8,500.00

Boiler house 1 1,000.00

Mechanical draft plant complete 4,700.00

Saving by using mechanical draft 13,567.00

$79,100.00

The original costs under the two conditions will be about as.
indicated. A total possible saving of $13,567 is thus shown, of
which $7167 is due to the reduction in nominal horse power made
possible by the introduction of mechanical draft.

A problem that has to be faced sooner or later in most boiler
plants is that of increased capacity. This differs from that just
presented in that the chimney already exists, and it becomes a
question whether the desired result shall be obtained by forcing the
existing boilers or by adding to their number. The former method
demands an increase in intensity of draft, which with a given chim-
ney, operating well up to its capacity, can only be obtained by con-
siderable increase of height at excessive expense, while with either
method a larger volume of air is required. As a result increased
output frequently demands not only more boilers, but a new or
hrgher chimney. Here mechanical draft steps in and presents a.
simple solution of the problem:

REL.-XTIVE COSTS.

2800 Nominal Horse Pozvcr Plant zvith Chimney Draft.

2 additional boilers $6,167.00

Settings, etc., for 2 boilers 1,250.00

Addition to 'building, etc 2,700.00

$10,117.00
2400 Nominal Horse Pozver Plant zvith Mechanical Draft.

Fan, dampers and ducts $1,500.00

Saving by using mechanical draft 8,617.00

$10,117.00

Considering the matter of increased output solely in the light
of comparative cost between the introduction of more boilers or
the introduction of mechanical draft, and disregarding any possible-
cost of change in the chimney, we may again take for illustration-
the plant of 2400 rated horse power. Suppose it is desired to-
increase its capacity to 2800 horse power, or by i6| per cent.
Then the relative costs under rhe two conditions will appear as here
indicated.

MECHANICAL DRAFT. 239

The saving actually secured by providing surplus capacity in
light, rapid-running fans, instead of in ponderous boilers, and the
higher efficiency of combustion obtained under proper arrange-
ments with mechanical draft, is most clearly shown by experience
in the merchant and naval marine. Here the matter of weight and
of space occupied is of great importance. Every pound in weight,
or foot of space saved leaves just so much more available for coal
and cargo.

We may now turn to that portion of our discussion which
relates to the cjuantitative efficiency of a boiler plant. No greater
waste occurs in modern steam-boiler practice than that which is
inherent m the employment of a chimney for the production of
draft, — namely, the loss of heat in the escaping gases. As the
chimney depends for its action upon the maintenance of a tempera-
ture difference between the internal gases and the external air, it
is manifest that with a chimney this waste can never be eliminated.
It may be palliated, it is true, by the building of higher chimneys,
so that the same intensity of draft may be obtained with a lower
stack temperature. But such means of providing for the utilization
of the otherwise vvaste heat is expensive. For instance, if, with
an external temperature of 60°, and an internal temperature of
500°, sufficient intensity of draft is produced by a chimney 100 feet
high, it will require a height of 175 feet to produce the same draft
when the temperature of the gases is reduced to 250°. In addition
the means provided for extracting this heat will increase the resist-
ance, and provisions for overcoming the same will have to be made
by greater chimney height.

In the case of a fan, hovv^ever, the power expended as meas-
ured in heat units necessary to produce the same results may,
under ordinary conditions, be only about one-seventy-fifth of that
necessary with a chimney. In other words, the fan renders avail-
able for utilization practically all of the heat wasted by the chimney,
while it possesses the further advantage of readily creating the
additional draft requisite when heat-abstracting devices are intro-
duced.

Messrs. Donkin & Kennedy in seventeen independent boiler
tests found the heat lost up the stack when no economizer was used
to range betw^een 9.4 per cent, and 31.8 per cent, of the total heat
of combustion. As it is not practicable to cool the gases to atmos-
pheric temperature, it is evidently impossible to utilize all of the
heat, but the ordinary economizer should, with mechanical draft,
show a saving of between 10 and 20 per cent.

240

ASSOCIATION OF ENGINEERING SOCIETIES.

The average results obtained by Roney from tests of nine
plants equipped with economizers and mechanical draft were as
follows :

Temperature of gases entering economizer 526.3 degrees.

Temperature of gases leaving economizer 269.6

Decrease in temperature of gases 256.7

Temperature of water entering economizer 150.4

Temperature of water leaving economizer 297.1

Increase in temperature of water 146.7

Fuel saving in per cent 14-64

Although not developed to the same extent as the economizer,
the air heater, by which the heat is transferred from the gases to the
air supplied to the furnace, has been introduced to a considerable
extent with satisfactory results. In experiments with the Marland

Fig. II. Steam Pressure Chart por Induced Draft Plant.

apparatus Hoadley showed that the waste of the flue gases could
be reduced to only 5 per cent, of the total heat value of the fuel
with an accompanying expenditure of only i per cent, of the steam
generated for driving the blower.

The importance of mechanical draft in the adoption of means
for utilizing the waste heat is well exemplified in the introduction
of retarders and of ribbed tubes. Both of these increase the resist-
ance, and almost invariably require fan draft to enable them to
create the saving of 5 to 10 per cent, which may be thus secured.

The facility with which the intensity of the draft and the
volume of air supplied can be regulated when a fan is employed
for draft production has always been recognized as one of the most
valuable characteristics of this method. Such regulation makes
possible the most perfect distribution of the air, and its reduction

MECHANICAL DRAFT.

241

to the minimum amount which will produce satisfactory combus-
tion.

Variable draft is necessary to maintain a constant steam
pressure. This is evidenced by the accompanying charts from a
mechanical draft plant. Fig. 1 1 illustrates the practical uniformity
of steam pressure maintained, while Fig. 12 indicates the consider-
able fluctuations of the draft required. The operation of the fan
is automatically regulated so that the slightest variation in the
steam pressure causes considerable change in the speed, and con-
sequently in the draft.

For the mere chemical requirements of the combustion of one
pound of ordinary coal, about 12 pounds or 150 cubic feet of air is
required. But under the "conditions of chimney draft this amount
is greatlv exceeded. Donkin & Kennedv showed in the results

Fig. 12. Draft Pressure Chart from Induced Draft Plant.

of sixteen tests that the air'supply ranged from 16. i pounds to 40.7
pounds.

The theoretical effects of an excess of air upon the combustion
of an ordinary anthracite coal are such that the ideal temperature
in the heart of the fire decreases with the excess, while the relative
weight of the products of combustion becomes greater. Although
the initial volume increases Vv'ith the excess it is to be noted that
the relative volume, after heating, remains practically constant
because of its lower temperature and consequent greater density.
As the gases pass onward through the tubes they become cooled,
but those of higher temperature part most readily with their heat,
and at the same time their volume and consequent velocity are
reduced, still further facilitating heat transmission. On the other
hand, the gases of lower initial temperature transmit their heat less

242 ASSOCIATION OF ENGINEERING SOCIETIES.

rapidly, and the final result is that within practical limits the
temperature of the escaping gases is highest with the greatest
excess of the air supply.

The fact just presented points toward the economy to be
secured by comparatively high rates of combustion when the
proper rate of heating surface to grate surface is provided. A high
combustion rate manifestly requires a thicker fire, which in turn
presents a better opportunity for contact between fuel and air with
consequent economy in the supply of the latter. Less air results
in a more intense fire, a higher furnace temperature, a greater trans-
mission of heat to the water within the boiler, and a resultant higher
evaporative efficiency. But the thicker fire requires a greater in-
tensity of draft to overcome the increased resistance, while the
relatively smaller area for passage of air necessitates a higher
velocity of that air, and, furthermore, the increased intensity to
produce this velocity must be proportional to the square of the
rate of flow. This condition is most readily met by the fan, which,
under normal conditions, produces an intensity exceeding that of
an ordinary chimney, and which can, without trouble, maintain the
highest practicable rate of combustion.

Whitham found that with a certain mechanical stoker in which
the air distribution was almost ideal, an excess of 85.6 per cent,
was used when the rate of combustion was 12 pounds, while almost
perfect evaporative efficiency was maintained when the rate was
45.4 pounds, and the air supply actually 11.2 per cent, below the
chemical requirements.

The actual fuel saving resulting from the introduction of me-
chanical draft is forcibly shown by the accompanying record of
eight voyages of the same vessel under identical conditions, except
as regards the means of draft production. It is to be noted that
the total consumption of coal per day was reduced 13 per cent.,
while the time occupied in making the voyage was decreased
nearly 5 per cent, by the substitution of forced draft.

•SAVING BY FORCED DRAFT ON STEAMSHIP "dANIA."

Consumption
Consumption for all pur-
Days Knots of coal poses per day
Conditions. steaming. per hour. per day. steaming.

Natvtral draft, 4 voyages 17.00 7.50 g.73 10.70

Forced draft, 4 voyages 16.21 7.58 7.76 9.31

Among the losses incident to combustion, that resulting from
the formation of smoke is absolute, for it is equivalent to directly
robbing the fire of a part of the fuel from which not only has no
heating effect been secured, but upon which heat has actually been
wasted in raising it to the temperature of the escaping flue gases.

MECHANICAL DRAFT. 243

Fortunately from a purely economic standi^oint, this loss seldom, if
ever, exceeds i per cent, of the total calorific value of the fuel. In
fact the prevention of smoke is not to be considered so much in its
economic aspect as in its relation to the stringent laws which are
being enforced in many communities. It thus becomes a question
of life or death, for, unless the smoke is prevented, the boilers
cannot be operated. For the prevention of smoke, sharp, intense
draft is necessary, properly regulated and capable of furnishing
the required amount of air, both below and above the fuel at the
very moment when it is most needed. This result can be best
secured by the introduction of mechanical draft, which is ordinarily
so regulated that the decrease- in steam pressure resulting from the
opening of the fire doors, the charging of the furnace or the clear-
ing of the fires instantl}' causes an increase of the speed of the fan
and in the intensity of the draft and the volume of air.

A loss incidental to poor draft is that due to the formation of
carbonic oxide. The formation of this gas instead of the complete
product of combustion, carbonic acid, results from the lack of air,
and may under adverse conditions mount up to a resultant loss of
5 or 10 per cent, and over of the calorific value of the coal. Thick
fires and large charges of cold fuel are certainly not conducive to
the ready flow of air under only slight pressure, such as is main-
tained with the chimney. Under these conditions any operation
of the flue damper, automatic or otherwise, only serves to vary the
volume of the air, but in no way increases the intensity of the draft.
This can only be secured by some means like the fan, which under
automatic regulation increases both the intensity of the draft and
the volume of the air when required. As a result, the pressure
forces the air in sufficient quantity tb all spaces between the fuel,
and renders the combustion practically perfect. Numerous tests
of the flue gases fail to reveal the presence of anv carbonic oxide
when mechanical draft is employed.

■ By far the most important of the factors connected with the
operating expense of a boiler plant is the cost of the fuel. When
burned under suitable conditions, the decrease in its cost far out-
strips the decrease in its efficiency, so that the solution of the prob-
lem involves itself with the provision of the proper conditions. As
a rule the cheap fuels, like the fine anthracites, require for their
combustion an intensity of draft, which the ordinary chimney is
incapable of producing. Speaking of the chimney in this connec-
tion, Coxe asserted that "It is always very difficult, in fact almost
impossible, to obtain with it sufficient blast to burn the smallest
sizes of anthracite coal, which require a strong and concentrated
draft."
17

244 ASSOCIATION OF ENGINEERING SOCIETIES.

It is here that mechanical draft presents itself as a solution, for
it fully meets the most exacting requirements as regards intensity,
costs far less for its installation than a chimney of equivalent
capacity, and is capable at all times of producing the blast necessary
for securing the best results in the furnace.

What these requirements are is evidenced by the accompany-
ing figures from careful tests by Coxe :

RESULTS OF TESTS OF PEA AND BUCKWHEAT COALS.

Pounds of
Rate of com- water evap-

bustion per orated from Maximum

sq. foot of and at 212° Air pressure limit to size

grate per lb. of in inches of of coal in

Kind of coal. per hour. coal. water. inches.

Oneida pea coal 13.63 8.56 0.375 y^

•' No. I Buckwheat 13.58 7.94 0.5 ■/«

" No. 2 " 11.40 8.60 0.625 }i

No. 3 " 11.34 8.65 1,04 %

Eckley No. 3 " 9.44 8.75 1.125 VV

These coals, which are among the smallest in size, were burned
on a special form of traveling grate, and the air pressure was main-
tained in the chamber beneath. It is noticeable, that with prac-
tically constant combustion rate and evaporative efficiency the
draft increases very rapidly as the size of the coal decreases.

RELATIVE EFFICIENCIES OF VARIOUS COALS.

Relative ef-
ficiency in
Fuel cost per cent.
Water ofevapora- measured

evaporated Relative ef- ting 1000 by cost to

from and at ficiency in lbs. of evaporate

212° by I percent. Cost of water from 1000 lbs.
lb. of Cumber- cqal and at Cumber-

Kind of coal, dry coal, land = 100. per ton. 212°. land = 100.

Cumberland 11.04 100 $3.75 $0.1698 100

Anthracite, broken 9.79 89 4.50 0.2297 74

Anthracite, chestnut 9.40 85 5.00 0.2660 64

Two parts pea and dust and

one part Cumberland.... 9.38 85 2.58 0.1375 123
Two parts pea and dust and

one part culm 9.01 82 2.58 0.1432 ifg

Anthracite pea 8.86 80 4.00 0.2259 75

Nova Scotia culm 8.42 76 2.00 0.1187 156

The comparative efBciency of various coals as determined by
Barrus is indicated in the accompanying table, which speaks for
itself. The evidence in favor of burning low-grade fuels is con-
clusive. Such results can, however, only be secured by positive
and intense draft.

It is true that as the quality of the coal grows poorer and the
size of the particles less, it becomes more necessary to provide
some special form of grate or stoker for its proper burning. But

MECHANICAL DRAFT.

245

even without an economizer to utilize the waste heat, the burning
of cheap fuel by mechanical draft will, under perfect conditions,
show a decided saving after due allowance is made for fixed charges
on the special furnace arrangements, and fdr the cost of operating
the fnn:

00000000

in I Water evaporated
•q from and at 212°
° Iper lb. of coal.

NO VO

_CO 00 >o _p

o CO 4»- "b

OJ o ^J ^J

^^ ^ 00 4^

ON ^ ^J 00 vO

« o ^ J^ «

_ M ^ VO O

.f>. Cn 0\ a> ^ 00
"m M '»-• ib "on "to

OJ OD cyi O O O

4^ c^ 0\ C/I OJ

1-1 M c*3 .f* en p\

0\ -vl ~J o\ ^ ■-■

OJ CJi .p». M O »-<

O to C*J M ^J en

en On C/i .t*. M 00
^4 OJ ^4 10 NO NO

The possible savings with low-grade fuels and mechanical
draft are still further evidenced by the accompanying table, which
shows, for a looo horse power plant, the annual saving, based on
312 days of ten hours each, which would result from the substitu-

246

ASSOCIATION OF ENGINEERING SOCIETIES.

tion of a cheaper fuel for, say Cumberland coal, costing in round
figures $4 per ton, and evaporating eleven pounds of water from
and at 212° per pound of coal. Under these conditions the annual
fuel expense would be $19,568. If the assumption be made that
a coal costing $2.50, and evaporating only nine pounds of water, is
substituted, the annual saving would be $4621. The fuel cost of
operating the fan, even if the exhaust steam was not utilized and
it required i^ per cent, of the total coal burned, would be only $224,
and if this is charged against the saving it would still amount to
$4397, a suni sufficient to show a most creditable reduction in
operating expense even if there was charged against it any addi-
tional labor and the fixed charges on a complete equipment of the
special appliances for burning the lower grade fuel. In general
practice a mere change of grate bars is sufificient to adapt a boiler
for burning almost clear yard screenings by means of mechanical
draft.

A reduction of over $125 per week, equivalent to $6500 per
year, has been made in actual practice in the case of a boiler plant
of 1000 horse power by the introduction of mechanical draft and
the burning of yard screenings ^vith a slight mixture of Cumber-
land.

A very interesting example of the reduction of fuel cost inci-
dent to the introduction of mechanical draft here follows. The
average load for the second year exceeded by about 3,0 horse power
that of the first year:

RESULTS OF OPERATION OF nOH.HR PLANT AT HOTEL IROQUOIS.
BUFFALO, N. Y.

JJ'itliout Mccluuucal Draff.

Kind of
coal.

No. of
tons.

Cost per
ton.

Total cost

of each kind

of coal.

Dec. I, 1892,

to
Nov. 30, 1893.

Dec. I, 1893,
to

Nov. 30, 1894.

f Hard Coal

I Screenings 232 $1-25 |

Hard Coal [ I1072.45 1

I Screenings 601.9 i-30 J

Soft Nut 696.95 2.20] [-

Soft Nut 15.04 2.25 i j

Soft Nut 1,759.6 2.30 j 19084-92 J

[ Soft Nut 1,445-75 2.40 j

With Mechanical Draft.

r Hard Coal

Screenings 1,299.95 $1.30 1

Hard Coal [ 15356. 24 j

Screenings 2,610.08 1.40 J !

Hard Nut 3.02 3.50 ] j

Soft Nut 843.03 2.10 j- I2333.69 J

i Soft Nut 255-9 2.20 j

Weight and
total cost of
coal for year.

4751.24 tons.

110,157.38.

5013 tons.

I7680.93.

MECHANICAL DRAFT. 247

Although the annual coal consumption was increased as was
to be expected with the lower grade of fuel, yet a reduction of
nearly 25 per cent, in the cost was efifected.

With the increasing interest in the possible reductions in oper-
ating expenses, more attention is being turned to the mechanical
stoker, both as a means of more economically and of more uni-
formly supplying the fuel to the furnace. As incidental to its
success, positive and automatically regulated draft is a necessity.
This is particularly true in the case of the modern forms of under
feed and chain feed machines. The forced method of mechanical
draft is generally employed and the necessary arrangements are of
the simplest character.

Of the advantages of mechanical draft which are purely quali-
tative in their character much might be said, but time will not
permit. It must sufifice to merely refer to the more prominent
points of advantage.

When the fan is employed for draft production the steel plate
construction, the comparative lightness, the portable character and
the absence of heavy foundations render extremely simple its
adaptation to the exact requirements. Being portable it is also
salable, and hence an asset of real value as compared with the
chimney. It may be used either for forced or induced draft and
placed where it will occupy no valuable space. It may be operated
by direct connected or belted engine or motor, and so proportioned
as to produce any desired draft pressure.

In operation the fan is both positive and flexible, independent
of the weather, but capable of regulation to the finest degree and of
adjustment to the necessities of the fire at any particular moment.
A mere increase in the cut-off of the fan engine brings about a
result only secured with a chimney at the expense of adding to its
height, while a change in the fan speed alters both the volume
handled and the intensity of the draft produced.

If this discussion of the influence of mechanical draft on boiler
efficiency has rendered clear the factors concerned, it has with equal
force shown that this influence is beneficial, — in many ways mark-
edly so. In the light of this fact the present active interest in the
subject points to the future consideration of mechanical draft as a
most important factor in steam boiler practice.

248 ASSOCIATION OF ENGINEERING SOCIETIES.

WATER AVASTE.

By Joseph C. Beardsley, Member Civil Engineers' Club of Cleveland.

[Read before the Club, June 13, 1899.*]

Water waste, while it is one of the most annoying difficulties
with which the water works engineer comes in contact, can scarcely
be considered an engineering problem, for the reason that the solu-
tion of it is perfectly obvious and the means of preventing it easily
available, providing only that the administrative officers are suffi-
ciently broad-minded and intelligent to appreciate the situation. It
is essentially an administrative rather than an engineering question,
and the only reason for presenting such a subject to an audience of
engineers is that it usually falls to engineers to educate the admin-
istrative officers up to the point of applying the one infallible remedy
and the water takers to accepting it as the only just means of esti-
mating their water rates.

Cleveland was fortunate in this respect, and meters have been-
in service here for considerably over twenty years without serious
objection from either administrative officers or water takers.

According to American ideas, air and water are on about the
same plane, — the supply of each should be equally free and limited
only by the demand, no matter of what nature, — and this idea was
perfectly proper fifty years ago, when every man had his own well
or running stream from which to draw his supply, which was
usually limited only by his physical ability in drawing it. Even
then, however, no man drew water from his well for. the pleasure
to be derived from spilling it on the ground.

Now, with the development of the modern city, we have all this
"drawing of water" accomplished for us, and instead of expending
physical effort we pay for it in cash.

We are able to have a supply at any point we desire it, and it
comes with the simple turning of a cock ; but with all this ease of
accomplishment comes the idea that it is not incumbent on us to use
any discretion in the consumption of what comes to us so easily.

This idea is fostered, too, by the manner in which payment is
made, in the great majority of cases, for this service. When one
has to pay only a certain fixed rate, based on the number of rooms
or fixtures, it is easy to fall into the habit of thinking that it really
makes but little difference how much water is consumed and to

*iManuscript received December 6, 1899. — Secretary, Ass'n of Eng. Socs.

WATER WASTE. 249

procrastinate g'oing for the plumber if any of the fixtures get out of
order and run continuously.

If any qualms of conscience do make themselves felt, we reason
that our neighbor is probably doing the same thing anyway, and
ask ourselves why shouldn't we? or, again, somewhat contradic-
torily, we feel that "just our one faucet running don't waste much
water." We should stop the leak very quickly, however, if the
supply depended on our own physical exertions, or if we had to pay
for it according to the amount we consumed.

The operating expenses of the Cleveland Water Works for
the year 1897 were $182,694.22.

The total cost of the plant, including that year, was about
$8,500,000, the interest on which, at 5 per cent., which would be a
fair average for the period covered, would be $425,000, making a
total of $607,694.22. The total water pumped during 1897 was
17,658.470,308 gallons.

This makes the cost of furnishing water about 3.4 cents per
1000 gallons, and in. these figures no allowance is made for the cost
of pipe extension, river tunnels and other minor construction which
is paid for out of the income without the issue of bonds.

This shows that while water is a cheap commodity, it still does
cost something, and it is perfectly apparent, since the expenses are
nearly proportional to the amount of water pumped, that water
rates can be reduced only by reducing the amount of water pumped,
or by cutting off alkthe improvements that are paid for out of the
revenue.

In Cleveland the minimum water rate with a private meter
(one set at the expense of the consumer) allows a consumption of
150,000 gallons at a cost of $8.00 per year.

These meters are set almost invariably on dw^ellings, and form
a fair basis of estimate of the necessities of a family. At this rate
each service would consume 410 gallons per day, and, estimating
six consumers to a service, would allow a per capita consumption
of 68 gallons per day. This would seem to be a liberal allowance,
and experience has shown that the consumption on private meters
seldom reaches this rate. In the few cases where it is exceeded it
is almost invariably found that there has been a leak or some un-
usual condition of consumption. Dwellings where private meters
are in service w^ould pay by assessment from $12.00 to $20.00 or
more, and under present conditions this rate cannot be reduced
without creating a deficit in the revenues of the department.

An expert commission appointed in the city of London to in-
vestigate the subject of water supply estimated that 42 gallons per

250 ASSOCIATION OF ENGINEERING SOCIETIES.

capita per day was a liberal supply, and in Paris the actual con-
sumption is 36 gallons. In Cleveland the consumption in 1897 was
136.3 gallons per capita per day, which was the highest in the his-
tory of the city except for 1895, when it was 136.6 gallons; 24.4
per cent, of the total pumpage for 1897 was metered, and this may
fairly be taken to represent the amount of water consumed for
nianufacturing and other similar purposes. Deducting this from
the average for 1897 leaves 103 gallons on the unmetered services.
Assuming our minimum private meter rate as a fair estimate of a
liberal supply (68 gallons), this would leave 35 gallons, or 34 per
cent, of all water not metered ; and, of course, the showing would
be much worse if we were to take the London or Paris figures, or
even those of the actual consumption on our private meters. This
cannot all be assumed to be waste, for we furnish a large amount of
free water for municipal and charitable institutions, to say nothing
of flushing paved streets and sewers and puddling trenches ; but a
large proportion of it is undoubtedly waste.

In many other cities the showing is much worse, notably in
Philadelphia, where our friend Mr. Trautwine has been making a
valiant, but so far, I believe, unsuccessful, fight for the introduction
of meters.

In a paper read by him before the Engineers' Club of Phila-
delphia, in October, 1898, some startling figures are given. In one
district of Philadelphia, containing 142 modern seven-room houses,
with 539 inhabitants and 782 water appliances, 22 of these appli-
ances were found leaking slightly and 32 were found running con-
tinuously.

The water consumed in this district during twent3'-four hours
V. as 1 19,800 gallons, or 222 gallons per capita per day, of which he
estimates that only 16,120 gallons, or 13.4 per cent., was used, the
remaining" 86.6 per cent, being wasted. The figures for water used
look rather small, as they allow only about 30 gallons per capita per
day ; but in any event it is easy to see that a large proportion of the
water furnished to this district was wasted.

In another district a similar examination showed that 63 per
cent, of all the water furnished to it was wasted.

The average daily consumption in Philadelphia has risen from
36 gallons per capita in i860 to 215 gallons in 1897. Practically
no meters are in service there.

In Cleveland the average daily consumption has risen from
7.75 gallons per capita in 1857 to 136.3 gallons in 1897, the increase
being practically continuous from year to year.

WATER WASTE. 251

Following is the daily per capita consumption in 1890 of sev-
eral cities :

Allegheny, 238 gallons, with no meters in service ; Buffalo, 186
gallons, with .02 per cent, of taps metered ; Richmond, 167 gallons,
with 1.4 per cent, of taps metered; Detroit, 161 gallons, with 2.1
per cent, of taps metered. JMilwaukee commenced in 1875 with an
average consumption of about 3,000,000 gallons per day, reached
a maximum of 35,000,000 gallons per day in 1894 and has since
declined, the maximum in 1897 being a little over 26,500,000 gal-
lons per day, an average of 88 per capita. This was for the single
month of July, and the average for the year is only 79 gallons per
capita per day. ^Meters have been in very general use in ^Milwaukee
since about 1890, and in 1897 there w^ere 20,000 in use, which I
should estimate to include at least 50 per cent, of all taps. It is
noticeable m the foregoing instances how the daily average de-
creases as the number of meters increases.

A still more striking illustration of the effect of the introduc-
tion of meters is furnished by the experience of Detroit. From
1870 to 1888 the consumption increased from 64 gallons per capita
per day to 204 during the latter year. During 1888 the setting of
meters was commenced, and it has been since steadily continued,
until in 1898 there were 5393 in service on 10 per cent, of the taps,
and including 20 per cent, of the consumption. Since 1888 the con-
sumption per capita per day has varied between 172 gallons in 1889
and 124.5 gallons in 1897. If the meters had not been set it is safe
to assume that the increase in consumption would have risen at the
rate that prevailed at the time of the setting of the meters. If this
had been the case, it would have been necessary to make additions
to the plant that would have involved an expenditure of $600,000
and an increase in operating expenses of $11,000 per year.

The meters are read and kept in repair without noticeable in-
crease in the operating expenses, and they cost only $151,000.

I might go on indefinitely to cite such examples, but enough has
been said, I think, to show that in cities where meters are not gener-
ally in use there is a rapidly increasing consuriiption of water, which
i? largely pure waste, and which involves large additional expendi-
tures every year for plant and operation, while there is no such
increase in cities where meters are in general use.

It may be of -advantage now to inquire into the manner in
which this waste occurs.

Quoting again from !Mr. Trautwine's paper, a faucet leaking
one drop per second wastes 5 gallons daily ; one dropping con-
stantly, but not running a continuous stream, 9 gallons; a third,

252 ASSOCIATION OF ENGINEERING SOCIETIES.

running the smallest possible steady stream, 14 gallons, and so on
up to one running full opening, 2357 gallons in twenty-four hours.

To come to more concrete examples, we had occasion some
years since to meter a number of church schools where there were
flagrant wastes of water. On one of these the assessment was
$10.00 per year. In ten days the meter had registered 14,500 cubic
feet, and if this rate had been continued the bill would have been
$208.80 for one year. Notices and warnings had been served
repeatedly on the school authorities, but it was not until the meter
was set that any serious effort was made to put a stop to the waste.
During this metering of the church schools, however, some political
toes must have got trodden upon, for we got an order that no more
meters must be set without the express sanction of the Mayor.
Fortunately the worst offenders had been metered by that time.

A more recent case occurred last month on Merwin street.
A foreman had been sent to set a meter for a new manufacturing
concern, and by mistake, there being two connections in front of
the place, got the meter on. the connection for the place next door.

As it was in a district which it is desired to meter generally,
no great harm was done, and the meter was allowed to remain.
-Next day the foreman went to set the other meter, and incidentally
took a reading of the first one, finding a consumption of over 1000
cubic feet in less than twenty-four hours. The assessment rate on
this place was $7.00 per year. The meter rate at the rate of con-
sumption for the first day would have been $146, but an investiga-
tion revealed a water closet that was running constantly and it was
immediately shut off.

Still another case was found in a peculiar way. A main was
being laid in a certain street, and in the course of operations it
became necessary to cut through a sewer connection coming from a
saloon. A constant stream of water was found running in the
sewer, and the saloonkeeper claimed to be totally unable to put a
stop to it.

The flow was finally stopped by shutting oft' the water connec-
tion for the place.

This was thought to be a favorable location for a meter, and
one was accordingly set.

The reading of the meter three days after it had been set was
3310 cubic feet, and the meter was going constantly. The assess-
ment rate on this place was $30.50 per year. The meter rate, unless
the waste is stopped, will be about $160.

If the annual diagram of daily consumption for a large city is
studied in connection with the daily changes of temperature, it will

WATER WASTE. 253

be observed that the pumpage runs up with extreme high tempera-
ture and also with extremely low temperatures. During periods of
extreme cold the waste is due, of course, to the practice of allnving
the water to run to keep it from freezing. With the high tempera-
tures the increase is due to excessive sprinkling, to the very general
tendency to allow the water to run until it becomes cool for drink-
ing and to the practice of using the water in lieu of ice for cooling
purposes. One summer not long since the owner of several large
tenement buildings was notified that the consumption on one of his
buildings was running to cjuite an unusual figure, and he desired us
to investigate the cause of it. We did so, and found six out of
about thirty tenants using their bathtubs as refrigerators. Perish-
able provisions were put in closed vessels, and then the water
was allowed to run constantly over them to keep them cool. All
other fixtures in the building had self-closing cocks, so the bath-
tubs had perforce to be utilized.

Cleveland is not by any means one of the most generally
metered cities in the country, but that meters have been set with a
consistent regard for measuring the large consumers is shown by
the fact that with only about 4 per cent, of the taps metered 24.4
per cent, of the entire pumpage is measured ; and the policy at
present is to continue, steadily if not rapidly, to place meters in the
older sections of the city, where the plumbing is most apt to be
defective and where experience has taught us that there is the
greatest unnecessary waste of water.

DISCUSSION.

C. O. Palmer. — What is the life of those meters?

J. C. Beardsley. — We figure this by work done by the meter
rather than by time. For a f-inch meter, the smallest size used by
us, we have taken 1,000,000 cubic feet, but I think this too high.
For a 4-inch meter 40,000,000 cubic feet has been our standard, but
I am of the opinion that this is too low for a Worthington meter.

C. S. Howe. — What is the accuracy of the meters?

J. C. Beardsley.^ — Meters are required to register within about
I per cent, when new ; after wear they register less. The first cost
of the meter is from $15.00 to $20.00 (depending on the kind) for
a f-inch meter, and the cost of setting is about $15.00. When set
at the consumer's expense he pays 40 cents per 1000 cubic feet of
water, with a minimum charge of $8.00 per year. Private meters
may be set in basements, and the cost of this is seldom over $5.00.

C. O. Palmer. — How often are the meters replaced?

J. C. Beardsley. — They are left in until they register the

-54 ASSOCIATlOxN OF ENGINEERING SOCIETIES.

amount we have estimated to be the Hmit for each size, unless there
are other reasons for changing.

M. W. KiNGSLEY. — Many kinds of meters have been tested as
to durabihty ; a Worthington f -inch meter was run to 3,000,000
cubic feet, with tests as to accuracy every 100,000 cubic feet. When
it had registered 1,000,000 cubic feet it was within 8 per cent, of
accurac}'.

RoBT. HoFFMAN.^ — How are they tested as to accuracy?

J. C. Beardsley. — By running water from meter into a gradu-
ated tank in different-sized streams from i -16-inch to full size of
the meter.

A. A. Skeels. — Does the meter affect the pressure?

J. C. Beardsley. — Very little.

John C. Trautwine, Jr. (correspondence).— Touching the
statement in my paper presented to the Engineers' Club of this city
October i, 1898, that in the district mentioned only thirty gallons
per capita per day were really used, Mr. Beardsley refers to this
estimate as looking "rather small," and it is therefore proper to
state how the estimate was formed. The measurement of the con-
sumption of the district was made by means of the Deacon waste
water detector (described in Proceedings Institution of Civil Engi-
neers, London, Vol. XLII, 1874-5, and in Proceedings Engineers'
Club of Philadelphia, Vol. XIII, No. 4, January, 1897), which
gives a continuous graphic record of the consumption. As the dis-
trict examined contained only small dwelling houses, "the quantity
running during the night (say from midnight to 2 or 3 a.m.), as
detected by the Deacon meter, was considered as wasted, and it was
assumed that during the day the waste went on at the same rate."
(Mr. Allen J. Fuller, assistant in charge of distribution, in report
of Bureau of Water, Philadelphia, for 1895, page 196.) The waste
thus estimated amounted to 192 gallons per capita per day, leaving
out of the total of 222 gallons only 30 gallons for "use". That this
■estimate is probably not much too low is indicated by the fact that
meter observations continued for more than three years on a
suburban dwelling with lawn, and occupied by a family of eight
persons, keeping one horse, showed an average daily per capita con-
sumption of only 34^ gallons. In this case the payments were by
schedule rates, the meter being used only for the purpose of gaining
information.

Noting Mr. Beardsley's remark that "practically no meters are
in service" liere, it may be well to state that at the close of 1898
1481 meters were in use, but these were all on manufacturing estab-
lishments or other large consumers. Councils not permitting the
adjustment of water rent on dwellings by meter.

GRADE CROSSINGS.
GRADE CROSSINGS.

By Augustus AJordecai, Member Engineers' Club of Cleveland.

[Read before the Club, December 26, 1899.*]

In the discussion of the question of ehminating grade cross-
ings of highways with railroads we must be careful to avoid preju-
dice. It is hard to overcome the natural impulse to make the cor-
poration bear as much of the burden as possible, whether it is right
or wTong to do so. "The corporation can afford it," we say. It is
hard even for an employe to divest himself of this feeling, and still
more so for one not so employed. Often we notice an employe
throwing away as w-orthless a bolt, for example, that has lost a nut ;
but if the bolt belongs to his bicycle, how carefully he preserves it
for future use.

Even to the most wealthy, the expenditure of millions of dol-
lars must be a matter of careful and judicious thought, not lightly
to be entered into.

Let us see what are the rights of the parties, the public and the
railroads, in the highway. They are equal as far as occupancy is
concerned, and both can go their ways, provided that in so doing
neither interferes unreasonably with the other. All are obliged to
use caution in the use of the common highway. The individual
must be careful he does not take any unnecessary chances in cross-
ing the tracks of the railroad. The electric company, if there is
one, must see that its conductor knows that the way is clear before
he allows its car to cross ; and the railroad company must, by
Avatchmen and gates, or by bell and whistle, warn the public, and use
every precaution to have the way clear before its train crosses the
highw^ay. Neither of the parties must obstruct the crossing for an
unreasonable length of time, consequently all would be benefited
equally by the elimination of the grade crossing if it were not for
certain conditions not common to both. By the abolition of the
grade crossing the public saves time, annoyance due to delays or to
precautions necessary for the prevention of accident, and damage
caused by the accident itself. A very large proportion of accidents
(judging from the records of the Erie Railroad, as high as 60 per
cent.) is due to the contributory negligence of the individual. The
street car company saves time — not a large item, as the man are paid
by the trip— and the liability of accident, which is a much more
important consideration wath them than with the steam railroad, as
its car is weaker and the passenger much more liable to injury.

*Manuscript received December 30, 1899. — Secretary, Ass'n of Eng. Socs.

256 ASSOCIATION OF ENGINEERING SOCIETIES.

The steam railroad saves the expense incident to watching the cross-
ing, an expense which legally, but perhaps not justly, it is forced
exclusively to bear; the time which would be lost in taking pre-
caution against accident (a larger item than in the case of an
electric railroad, as the steam road generally has many highways
to cross) and the liability of injury in case of accident, which, as
shown, is lower in the case of the steam railroad than with the
electric road or with the public. The laws of New York make it
obligatory on the part of the parties interested to abolish the cross-
ing if the Board of Railroad Commissioners says it should be
abolished ; the railroad company paying one-half, the city or village
one-quarter and the state one-quarter of the cost. In Ohio, if the
railroad company and the municipal authorities agree that the cross-
ing may be abolished, not more than 35 per cent, of the cost is paid
by the municipality and not less than 65 per cent, by the railroad
company. This is certainly not burdensome on the municipalityj
especially when we remember that the railroad company, being a
large taxpayer, eventually pays no mean proportion of the 35 per
cent, charged to the municipality.

In the design for the work, if the railroad is put under the
highway, there should be not less than 18 feet headroom and 2 feet
for floor of bridge. In Ohio there is a statute obliging an obstruc-
tion over a railroad track to be at least 21 feet above the top of rail,
but I think this should be amended so as to give the Railroad Com-
missioner some discretion in the matter. Out on the open road,
where trains run fast, and in the days before the nearly universal
use of air brakes had greatly diminished the brakeman's duties in
running from one car to another to set the brake, it might have been
proper to require such headroom; but in these days, and in cities,
where there is slow movement and where the locomotives and
cars are equipped with air brakes, it does not seem necessary in all
cases ; and in fact other cities are adopting less headroom, and the
Erie Railroad has been running for years in this city under bridges
of very much less headroom, properly protected, without accident.
I think the headroom should not be less than 18 feet, however;
first, to allow for the future probable increase in height of locomo-
tives and cars, which are constantly growing higher and higher, and
also to allow a brakeman, if he is on top of a car, to sit down with-
out being struck. If it were impressed on him that he could not
stand, but might sit down, on going through a city, the liability to
accident would be much reduced.

If the highway is put under the railroad there should be at
least 13 feet headroom allowed, with 2 feet for floor of bridge at

GRADE CROSSINGS. . 257

highways where there is or may he an electric railroad, and 12 feet,
with 2 feet for floor of bridge, at highways where no electric rail-
way is likely to be built. This will not allow the use of a double-
decked electric car, but I think it is not inir-easonable to make this
restriction. In fact, it must be remembered that the placing of the
highway under the railroad immediately restricts materially the
height of the vehicle and its load that can pass under the bridge, a
restriction that, except for the trolley wires, which I hope are but
temporary, is not encoimtered in any other part of the highway.
The gorgeous band-wagon of the circus, for instance, or the floats
of an industrial parade will have to take another route, whereas the
railroad equipment is restricted just as much by other things, such
as the heights of the top bracing on bridges or the cross-section of
the tunnels, etc. This is one of the strong arguments in favor of
placing the highway above the railroad.

The width of the highway should not be restricted . unless
under exceptional circumstances. It is true that London Bridge,
with its enormous traffic, is but 56 feet wide, and that Chestnut
Street Bridge, in Philadelphia, is but 40 feet wide ; yet room seems
to be necessary in this bustling life of ours, and the people are
entitled to it. The grades on the highway approaches should be
not more than 5 per cent. This is the grade used in Chicago, and
many cities have steeper natural ones ; certainly Cleveland has.
I mention Chestnut Street Bridge because it is on one of the main
thoroughfares between populations nearly twice as large as in
Cleveland, and carries two street railroad tracks.

Nor should the width of the railroad be curtailed. It is hard
to foresee what conditions may arise, and allowance must be made
for future growth. If a highway becomes congested there are
other highways, but to obtain other railroad tracks is another mat-
ter ; always expensive, often- impossible. The grades on the rail-
road should not be changed to make them a burden at the time or
in the event of any possible future improvement to the railroad
property, and for this reason great care must be taken in raising the
elevation of the railroad tracks or in increasing their grade, as such
change might involve a very serious burden on the property. There
may be verv little, if any, reserve power in a locomotive. It is
usually loaded to its capacity ; whereas, in the individual and electric
car, within certain limits, there is ample reserve power, and the
same is true of most horses. The railroad is an essential and admi-
rable instrument in the growth and development of a city. It is a
tool not to be abused and knocked about, but, like all other good
tools, to be handled somewhat affectionately ; to be kept always neat
and clean and in thorough working order.

258 ASSOCIATION OF ENGINEERING SOCIETIES.

Other things being equal, it is certainly lighter, pleasanter, in
every way better, to raise the highway. This may or may not in-
volve the depression of the railroad tracks. If the tracks can re-
main as they are, well and good. In that case we have only to see
that the structure and its supports are so constructed that they shall
not interfere with the railroad and its operation ; and, although the
railroad authorities are seemingly actuated by selfish motives, it is
pretty safe to conclude that they are fairly good guides to follow in
these and in similar cases. If the tracks must be raised or lowered
in order to avoid steep approaches or excessive property damage,
it may be wise to lower them, the depth depending oh circumstances.
Through the residence district of a great city it may be well to
lower the tracks the full distance required. An elevated track is
an eyesore, noisy, extremely ugly and altogether horrid. Through
the manufacturing districts of the same city it is better to elevate
them, other things being equal ; or, at most, to depress them but a
few feet, so that existing manufactories can meet the changed con-
ditions without excessive expenditure, and that adjoining unim-
proved property owners may not be deprived of the use of their
property for the best purpose to which it can be put, as might be
the case if the railroad tracks were depressed the full distance
required. It is also true that, especially with railroad tracks, it is
much easier and cheaper to raise them than to depress them.

The difficulties incident to the location of sewers, water mains,
etc., in the depression of the tracks have no terrors for the engineer
who is familiar with the work done by the cable car company in
New York city, or with that proposed to be done by the Rapid
Transit Company.

The question of damage to abutting property on the highway is
always comparatively an important one where conditions are
changed ever so slightly, and is always very thoroughly considered
in cases of this kind ; l^ut it should not be given undue importance.
Granted an equitable division, the cost is a secondary consideration,
as the work is for all time and should be done in the best manner.
Then again, the damage is only the cost of changing the buildings
and other improvements to meet the changed conditions. The
value of the land itself is rarely changed, for that depends upon the
ease of access to and from a more or less crowded thoroughfare.
For instance, the most valuable land in the world is at the intersec-
tion of Fleet street and the Strand in London, because of the
crowds passing it. The corner of Broad and Wall streets, in New
York, is possibly equally valuable, and especially in a raised high-
way this condition is not changed. What, then, is the damage to

GRADE CROSSINGS. 259

the improvements? If, for instance, all the buildings at the corner
of Euclid and Willson avenues and 200 feet each side were wiped
out by fire in a night, the most sensational report would not
put the loss on the buildings alone at any enormous figure. The
insurance companies would certainly pay much less, and I do not
doubt that the owners' sworn estimates of their value made to the
tax assessor would show a very much further reduction from the
amount the insurance companies would be called upon to pay ; and
again, the buildings in the aggregate would be damaged much less
than half their value. Looked at in this way, the damage is reduced
to a less formidable proposition. The trouble consists in arousing
the antagonism of the owners themselves, who generally, and by
the very nature of things, are men of influence and standing, and
of much more power in the community than is the intangible stock-
holder of the railroad company, for instance ; so that it is easy for
them to obtain excessive judgments, especially when municipalities
and corporations are to pay them. The process of awarding dam-
ages is human, therefore fallible. It might be better to appoint one
or a few good men as commissioners to award them in place of the
ordinary jury, as has been done in Xew York; l)ut this may seem
arbitrary to many accustomed to the old way.

In the actual performance of the work, that party who is in
position to do any part of it best and most cheaply should do it.
The municipality should settle the damages with abutting owners;
and, as it can borrow money more cheaply than can the railroad
companies, it might, if desired, lend its credit to the latter under
well-considered conditions. The railroad companies might build
part or the whole of the structure. The general principles being
agreed upon, the details can easily be arranged.

As far as the maintenance is concerned, each party should
maintain that part worn or used by it exclusively, and those parts
where failure w^puld render it liable in damages to others ; where
several parties use the same part, or where several would be liable,
the expense should be divided proportionately.

DISCUSSION.

H. C. Thompson.— ^In the question of the elimination of grade
crossings of steam railroads there are three parties concerned, — the
city, the railroad and the manufacturers located on the line of the
railroad, — each of whom have interests which should be carefully
considered; the object being the harmonizing of these interests so
that the expense of the improvement shall be equitably distributed.

The necessity of the improvement cannot be questioned. It
■grows every day, as the population and business of the city increase,
and the longer it is postponed the greater will be the cost.

18

26o ASSOCIATION OF ENGINEERING SOCIETIES.

The crossings should be made above or below the grade of the
railroad, as the conditions of each particular crossing are presented.
The full width of the street should be maintained in all cases. The
city has a moral right to demand this improvement, and all inter-
ested should be obliged to acquiesce in whatever arrangement is
finally agreed upon.

The railroads were on the ground first, the city having grown
to them and around them, thereby creating the demand for a change
in the crossings.

It is fair to presume that when the railroads were built the con-
struction followed the lines of economy with respect to the utility
of the line as compared with the ground on which it was built,
although possibly better results could have been attained at an in-
creased outlay of first cost. Assuming this to be true, the expendi-
ture of an additional sum would not destroy the present effective-
ness or lessen the economy in operation as compared with what now
obtains. This expenditure would be necessary to make the present
gradients conform to the improved crossings, involving structures
above, below and at the grade of the present roadbeds. The rail-
roads have contributed to the growth of the city, and at the same
time have profited by this growth, which has enhanced the value of
their own property as well as that in the immediate vicinity.

The interests of the manufacturers and those of the railroad
are to a great extent mutual, the manufacturer depending on the
railroad for transportation, and the railroad deriving a great por-
tion of its profit from the manufacturer. The manufacturer on the
line of the railroad would have to conform to the new gradient of
the railroad, because the conditions which obtain are more elastic,
so far as he is concerned, than with the railroad, where the object
it) to preserve the present effectiveness with economy in operation.

It is to the interest of the city to encourage the manufacturer,
because he contributes to the growth of the city ; and, incidentally,
the railroad enables the city to give this encouragement. The
obvious conclusion is that all the interests involved are closely
allied, and to a great extent mutual.

It would be premature at this time to say definitely how the
expense should be divided. This could be arrived at intelligently
only after a fair consideration of all the details of a perfected plan
of operation, and, to the mind of the writer, the proper way to
arrive at this end would be through a tribunal created expressly
for this work, in which all the interests should be fairly represented.
This tribunal should be clothed with power to determine on all ques-
tions which may arise, and should be composed of men skilled in
this line of work, and able to give their time to a full consideration
of the whole subject.

As

SOCIATION

OF

Engineering Societies.

Vol. XXIII. JULY, 1899. No. i.

PROCEEDINGS.

Technical Society of the Pacific Coast.

Regular Meeting, June 2, 1899. — Called to order at 8.30 p.m. by Presi-
dent Percy. The minutes of the last regular meeting were read and ap-
proved.

Upon ballot, the following gentlemen were declared duly elected to as-
sociate membership : Alexander G. McAdie, U. S. Weather Bureau, and
Erland Gjessing, of San Francisco.

The following applications were made and referred to 'the Executive
Committee :

For members — Henry S. Button, architect, of San Francisco ; proposed
by G. W. Percy, H. C. Behr and Edw. F. Haas. Franklin C. Prindle, civil
engineer, U. S. Navy, San Francisco ; proposed by Otto yon Geldern, G. W.
Percy and Marsden Manson. Colonel S. M. Mansfield, corps of engineers,
U. S. A. ; proposed by Otto von Geldern, A. Ballantyne and C. E. Grunsky.
Major W. H. Heuer, corps of engineers, U. S. A. ; proposed by Hubert
Vischer, A. Ballantyne and Otto von Geldern. Major C. E. L. B. Davis,
corps of engineers, U. S. A. ; proposed by Otto von Geldern, Hubert Vischer
and A. Ballantyne. For associate — Geo. P. Wetmore, concrete builder, San
Francisco ; proposed by G. W. Percy, H. Barth and Otto von Geldern.

Mr. A. G. McAdie addressed the members on the subject of "Storm
Structure," presenting an interesting description of the work and methods of
the U. S. Weather Bureau, which was illustrated by fine lantern slides made
for the purpose of the lecture.

The President expressed the thanks of the Society to Mr. McAdie and
adjourned the meeting until the first Friday in August.

Otto von Geldern, Secretary.

Montaua Society of Engineers.

A SPECIAL meeting was held in the art room of the Butte Public Library,
Butte, Montana, on July 8, 1899.

Meeting called to order by President Eugene Carroll at 8.30 p.m. ; Mr.
R. A. McArthur acting as Secretary pro tern.

Nine members and three visitors were present. The minutes of the pre-
ceding meeting in Helena were read and approved.

2 ASSOCIATION OF ENGINEERING SOCIETIES.

Messrs. John C. Patterson and Frederic J. Taylor were appointed a
committee to prepare a memoir in honor of the late Henry C. Relf. It was
found that less than one-half of the members had voted upon the amend-
ment to the Constitution. Consequently the letter ballots were not opened
and canvassed, but deferred to the next meeting.

Adjourned. A. S. HoveYj Secretary.

Ass

OCIATION

OF

Engineering Societies.

Vol. XXIII. AUGUST, 1899. No. 2.

PROCEEDINGS.

Detroit Eugiueering- Society.

The 40th regular meeting of the Society was held at the Hotel Ste.
Claire, Friday, ]May 26, 1899; President W. J. Keep presiding.

The paper of the evening, "Deposits in the Pipe System of Detroit
Water Works," was read by Mr. C. W. Hubbell, Civil Engineer to the Board
of Water Commissioners, and discussed by several of the members present.

Adjourned. Henry Goldmark, Secretary.

The 41st regular meeting of the Society was held at the Hotel Ste.
Claire, Friday, June 2^, 1899.

Twenty-one members and guests were present. In the absence of all
the officers of the Society, Prof. C. E. Greene was elected chairman of the
meeting, and Mr. S. H. Woodard Secretary.

The name of John H. Galway was proposed for membership.

The paper of the evening was read by Alexander B. Raymond, upon
"House Drainage," and discussed by Prof. Greene and Mr. Hubbell.

Adjourned.

Engineers' Club of Cincinnati.

107TH Regular AIeeting, Cincinnati^ O., June 15, 1899. — Dinner was
served at 6.15 p.m. ; eighteen members and three visitors present.

The regular meeting was called to order at 7.10 p.m.; with President
Hazard in the chair.

Minutes of the meeting of May 16 were read and approved.

The Secretary read a letter from Mr. W. B. Ruggles, dated Matanzas.
Cuba, and addressed to Mr. R. L. Read, with which he sent a gavel for pres-
entation to the club. The head of the gavel is made from wood taken from
the Santa Christina Barracks at Matanzas, built some, fifty years or more
ago. On motion, the Secretary was directed to send to Mr. Ruggles the
thanks of the Club for his kindly remembrance.

Dr. Thomas Evans, instructor in technical chemistry at the University
of Cincinnati, read a paper on "Fuel Gas." devoted principally to discussions
and descriptions of processes for the manufacture of fuel gas for use in
metallurgical works.

4 ASSOCIATION OF ENGINEERING SOCIETIES.

Mr. L. E. Bogen read a paper under the title of "The Testing of Iron and
Steel," in which he reviewed what has been accomplished in determining
the quaHty of these metals by microscopical inspection.

Both papers were quite freely discussed.

Adjourned. J. F. Wilson, Secretary.

Technical Society of the Pacific Coast.

Regular Meeting, September i, 1899. — Called to order at 8.30 p.m. by
President Percy. The minutes of the last regular meeting were read and
approved.

The following names were declared elected upon count of ballot :

Members — Paul W. Prutzman, chemist, San Francisco; Thos. Mor-
rin, mechanical engineer, San Francisco. Associate member — Richard
Keatinge, concrete builder, San Francisco.

A letter was read from the Southern Pacific Railroad Company, stating
terms on which an excursion to Palo Alto could be conducted. It was re-
ferred to the Board of Directors, with power to act.

Thereupon, Mr. G. A. Wright, aixhitect, read a paper on the subject of
"The Quantity System of Inviting Bids from Contractors, and its Application
to Engineering and Architectural Practice," a discussion of which was par-
ticipated in by many of the members present.

Adjourned. C. E. Grunsky, Acting Secretary.

A

SSOCIATION

OF

Engineering Societies.

Vol. XXIII. SEPTEMBER, 1899. No. 3.

PROCEEDINGS.

Boston Society of Civil Eiigiueers.

Boston, Mass., September 20, 1899. — A regular meeting of the Boston
Society of Civil Engineers was held at Chipman Hall, Tremont Temple, at
8 o'clock P.M.; President C. Frank Allen in the chair. Sixty-seven members
and visitors present.

The Secretary being absent, on motion of Professor Swain, Mr. E. W.
Howe was appointed Secretary pro tern.

The record of the last meeting was read and approved.

The President appointed Mr. R. A. Hale a committee to distribute, re-
ceive and count the votes for new members. Messrs. Charles B. Breed,
John H. Emigh and Orville J. Whitney were elected members of the Society,
forty-two ballots having been cast for all the candidates.

Prof. George F. Swain, for the Committee on the Amendment of the
By-laws, read the following report :

The committee appointed to draft the proposed change in Section 5 of
the By-laws begs leave to recommend that paragraph 2 of Section 5 be
amended so that it shall read as follows : "Of the candidates for any office,
the one having the largest number of legal votes by the letter ballot shall be
declared elected. Should there be a failure to elect any officer on account of
a tie, the meeting shall proceed to elect such officer by ballot from among the
candidates so tied, a majority of the votes cast being required to elect."

George F. Swain, ]
Alexis H. French, - Committee.
Frederic P. Stearns, J

On motion of Fred. Brooks, the report of the committee was accepted
and the committee discharged. Mr. Brooks moved that the amendment be
adopted, and it was voted that the amendment be printed in the notice of
the next meeting. Action on the adoption of the amendment was post-
poned until the next meeting, as required by the By-laws.

Mr. H. a. Carson, for the committee, consisting of himself and Mr.
Otis F. Clapp, read a memoir of Mr. Charles H. Swan.

The following letter was read from Mr. Charles A. Pearson, member of
the Society :

Boston, Mass.^ September 20, 1899.
Prof. C. Frank Allen, President of the Boston Society of Civil Engineers:

Dear Sir : — It gives me pleasure in presenting through you to the Bos-
ton Society of Civil Engineers a portrait of the late Thomas Doane.

6 ASSOCIATION OF ENGINEERING SOCIETIES.

That Mr. Doane's personal qualities were appreciated by the Society is
fully attested by the number of years which he served as its President, and
also by his membership on important committees relating to the welfare of
the Society.

In presenting this portrait I feel that it is but a fitting memorial in
remembrance of one with whom I was intimately associated for thirty years.

His example was one worthy of following. His presence commanded
respect, his opinions attention. His daily life was one of Christian love,
purity and charity. Yours very respectfully,

Charles A. Pearson.

The portrait was accepted on behalf of the Society by the President with
a few appropriate remarks. On motion of Prof. G. F. Swain, seconded by
]\Ir. H. A. Carson, the thanks of the Society were voted to Mr. C. A. Pear-
son for the portrait of Mr. Doane.

President Allen then read a memoir of Mr. Doane, prepared by a com-
mittee consisting of Messrs. Desmond FitzGerald, C. Frank Allen and C. A.
Pearson.

On motion of Mr. C. W. Sherman, it was voted that the Society tender
its thanks to the Pennsylvania Steel Company, contractors for the Fort
Point Channel Bridge, and to the Lowney Chocolate Company, for courtesies
extended on the occasion of the excursion of July 19, and to Benj. W. Wells,
Superintendent of Streets, Boston, the New England Sanitary Product Com-
pany and the Metropolitan Sewerage Commission, for courtesies extended
on the occasion of the excursion of August 23.

Mr. H. A. Carson, Past-President of the Society, then gave a very
interesting account of his recent visit to Egypt and Europe, and exhibited a
large number of lantern views.

Adjourned at 10 p.m. E. W. Howe, Secretary pro tern.

Charles Herbert Swan. — A Memoir.

By Howard A. Carson and Otis F. Clapp, Committee of the Boston
Society of Civil Engineers.

[Read before the Society, September 20, 1899.]

Charles Herbert Swan, who was a member of
this Society for about seventeen years before his death,
was born in Boston, August 17, 1842. Several of his
immediate ancestors were prominent in this commun-
ity. One of his great-grandfathers was a major in the
Revolutionary War. On his father's side, Charles was
related to the Tufts family, after whom Tufts College
was named. Deacon James Loring, his grandfather on
his mother's side, was founder of The Watchman, the
well-known Baptist paper. His father, James G. Swan,
formerly of Medford, is still living, in the State of
Washington. His mother was Matilda Loring Swan, of Boston, who died
in 1863. Charles was the older of two children. Miss Ellen M. Swan, his
sister, lives in Boston.

In his youth he lived on Chapman place, near School street. He at-
tended the Boston public schools, including the Brimmer and the Latin
School, and, in March, 1859, entered the Lawrence Scientific School, from

PROCEEDINGS. 7

which he was graduated in 1861. One of his classmates and friends at the
Lawrence Scientific School, Roberdeau Buchanan, now an assistant in the
Nautical Almanac Office, Washington, gives some incidents in regard to
that portion of his life. Young Swan was remarkably quick mentally, and
seldom failed to go through the demonstrations at the blackboard. The
students were not marked and graded for their recitations, but he stood high
in his studies. One day, after Professor Eustis had left the hall, Buchanan
and Swan were engaged in their drawings, when the latter was overheard
whistling the overture to "The Messiah," and later these friends and others
often met to practice classical and other music. Swan playing the flute.
Soon after taking their degrees of Bachelor of Science they both entered
the office of C. L. Stevenson, civil engineer. The Civil War was then just
beginning, and, as they had imbibed a number of military ideas from Pro-
fessor Eustis, they determined to study fortifications together, and went
through the course which was then pursued at West Point, making the cus-
tomary drawings.

Later Mr. Stevenson was chief engineer on the construction of the
Charlestown Water Works, and young Swan was engaged by him during
its whole three years' progress. After the preliminary surveys were finished,
he was assigned to the city division, in charge of laying the street mains.
At the completion of the work a marble slab was erected at the pumping
station in commemoration, and on this slab his name may be found among
those of the other engineers, the commissioners, the Mayor, etc.

At a later time he was one of the engineers connected with the construc-
tion of the Salem Water Works, and he remained there until the fall of
1869. the last year of the time as acting chief engineer. He went from there
to Providence, R. L, where he was one of the assistant engineers to J. Her-
bert Shedd, on water and sewerage works. While in Providence he was the
first engineer to work out an abbreviation of the Kutter formula applicable
to sewerage work, constructing a valuable set of sewer diagrams based upon
that formula. He was specially connected with the numerous investigations
entered into in the development of the plans for the water works and sewer-
age systems, and his services were valuable and highly appreciated.

He remained in Providence until 1881, except that he spent a part of
1874 and 1875 in Europe on account of his health. In 1880 he had serious
eye trouble and was obliged to discontinue work for three years. He moved
to Boston in 1881.

In 1884 he went to Europe with Samuel M. Gray, City Engineer of
Providence, to study the sewerage systems of various European cities, and
prepared the historical portion of the resulting report.

In 1886 he was employed, for about six or eight months, by Rudolph
Hering, then Chief Engineer of the Chicago Water Supply and Drainage
Commission, as a special assistant, to work out the problem of disposing of
the sewage of the city of Chicago by filtration on land, and to estimate the
cost thereof. Between the fall of 1887 and the spring of 1888 he was en-
gaged, in making a study, for the Water Supply and Sewerage Committee of
the Massachusetts State Board of Health, of the scheme of disposal of the
sewage of the North Metropolitan Sewerage District by chemical precipita-
tion.

He was teacher, for one term, at the Lawrence Scientific School during
the absence of Professor Chaplin, in the spring of 1889, giving instruction
in the strength of materials, in hydraulics, and in water supply and sanitary
engineering.

8 ASSOCIATION OF ENGINEERING SOCIETIES.

In 1889 he was appointed one of the assistant engineers on the Metro-
politan Sewerage System, and continued to be more or less actively con-
nected with that work until the time of his death. He was specially en-
gaged, in this connection, with all of the laborious and important investiga-
tions and studies as to the flow of sewage in. the siphons and all other
portions of the system and in investigations as to the stability of chimneys
and various other structures.

From October, 1894, to September, 1897, he was an assistant engineer
on the Boston subway, and made numerous studies for changes in sewers,
pipes, etc. During a portion of this period he was also employed on the
Metropolitan Sewerage System.

In the winter of 1897-1898 he made a report on a projected joint system
of sewerage for Salem and Peabody. The question at issue was chiefly the
apportionment of the cost between the two. Mr. Swan was employed by
Salem.

From 1898 to 1899 he was again devoting his whole time to the Metro-
politan Sewerage work, where he had charge of the special hydraulic studies
and the preparation of the text of the engineering portion of the report for
the high level gravity sewer for the relief of the Charles and Neponset River
Valleys.

He became a member of the American Society of Civil Engineers in
1870, and of the Boston Society of Civil Engineers in 1882.

Soon after his twenty-first year he was received into the First Baptist
Church of Boston. In 1872 he and Mrs. Swan joined the Roger Williams
Free Baptist Church, of Providence. Not long after his removal to Boston,
in 1881, he was received into the First Free Baptist Church, of which he was
a member until his death. At the time of his death he was the President of
the legal society managing the property of this church.

Those for whom and with whom he worked testify to his ability, his
careful industry and the marked excellence of his work. He was very fond
of books and had a good collection of his own, and he took great interest
in systematically arranging and indexing them. His love of music and his
skill in playing the fltite have already been mentioned. This taste and skill
continued through life and were the means of giving pleasure to many of
his friends. During his later years he became much interested in photog-
raphy, and was skilled in taking and developing photographs and in making
transparencies. He was quiet and unobtrusive, but among those who knew
him well he was an exceedinely entertaining and pleasant companion. The
writers, and others who knew him intimately for years, cannot recall ever
hearing him speak an uncharitable or unkind word.

June 30, 1870, he married Miss Carrie Cheney, a daughter of President
O. B. Cheney, of Bates College, Lewiston, Maine. His widow and four
sons survive him, the youngest being nineteen years of age. His domestic
life was an ideal one. He was a loving husband and father.

Though not as robust as many men, and though at times suffering
somewhat from a weakness of the eyes, he generally enjoyed good health,
and there was every prospect that he would live and work for many years
to come. On Tuesday, April 12, he visited the Metropolitan Sewerage
office for the last time. The next day he was suffering somewhat from ton-
sillitis. On Sunday morning, April 16, he was found to be afflicted with
malignant diphtheria. After some hours of apparent unconsciousness he
died on Monday morning, April 17, 1899, aged nearly fifty-seven years.

PROCEEDINGS.
Engineers' Clnb of St. Louis.

September 20, 1899. — Meeting was called to order at 8.20 p.m.; Presi-
dent Colby presiding. Sixteen members and four visitors were present.
The minutes of the 492d meeting were read and approved. The minutes of
the 277th and 278th meetings of the Executive Committee were read. The
application of Mr. O. J. Barwick having been recommended by the Executive
Committee, he was balloted for and declared elected. The names of
Messrs. E. B. Fay, E. A. Cordes, F. D. Beardslee, O. M. C. Bilhartz, Frank
Ringer and W. J. Fogarty were proposed for membership.

The paper of the evening, entitled "Discipline," by Mr. Willard Beahan,
was then read by the Secretary in the absence of the author.

In this paper the relations that should be maintained between employer
or superintendent and employes were discussed, being divided under three
heads: first, the right of the men to be heard; second, their right treatment;
third, wages.

Under the first it was maintained that a hearing should always be given
the men, whether they came as individuals, committee or society, and that
by so doing the answer, whether acceding to their requests or not, if given
with the reasons for it, would usually be gracefully accepted.

Under the second head, the necessity of seeing that the men's comfort
and well-being be carefully looked after was set forth. Also that usually
the head man should fare no better than the men if it is desired that they re-
main contented.

The question of wages was next considered and the adoption of a slid-
ing scale of payment advocated, as in this way the most valuable men are
graduall)^ enabled to earn more and will thus be kept for long periods of
time, to the benefit of their employers.

Mr. Beahan also went into the question of strikes, treating of their pre-
vention and treatment after occurring.

The discussion following was participated in by Messrs. Bryan, Fish,
Borden, Bouton, Colby and Von Ornum.

There being no further business, the meeting adjourned.

E. R. Fish, Secretary.

Montana Society of Engineers.

A MEETING of the Society was held in the Butte Public Library, Butte,
Montana, on September 9, 1899. Meeting called to order at 8.30 p.m. ; Mr.
Francis W. Blackford in the chair, Mr. R. A. McArthur Secretary pro tern.

The applications for membership of Richard R. Vail and Albert Koberle
were read and referred to the Trustees.

A vote of thanks was tendered Senator T. H. Carter for securing for the
Society the Presidential messages and papers, consisting of a number of
nicely bound volumes, containing all the messages of the Presidents.

Messrs. Page and Flood were appointed tellers to canvass the ballots
on the proposed change of constitution, changing the headquarters of the
Society from Helena to Butte. The vote was : Yes 56, no 6. Total vote
cast 62. Whereupon the chair declared the amendment carried. Thus Butte
becomes the headquarters of the Society.

A committee consisting of Messrs. Aug. Christian, John Gillie and F. J.
Smith was appointed to nominate officers for the ensuing year.

Adjourned. A. S. Hovey, Secretary.

ASSOCIATION OF ENGINEERING SOCIETIES.
Enciueers' Club of Cinciimati.

io8th Regular Meeting, Cincinnati, Ohio, September 21, 1899. —
Dinner was served at 6.20 p.m. Eighteen members and three visitors.

The regular meeting was called to order at 7.30; Vice-President Pun-
shon in the chair.

Minutes of the meeting of June 15 were read and approved.

Application for active membership was received from Mr. Frank L.
Fales, Assistant Engineer, Chief Engineer's Office, Board of Trustees, Com-
missioners of Water Works.

Mr. W. M. Venable, who was announced to read a paper on "Camp
Engineering of Two Great Army Camps," described the work of the engi-
neer corps, with which he was connected during the late war with Spain, at
Camp Wikoff, at Montauk Point, N. Y., and at Camp Columbia, at Mariano,
Cuba, in the establishment of these camps and in improving the sanitary con-
ditions at them, more especially the former, which necessitated an immense
amount of labor on account of the large number of troops to be provided for
in the very short time allowed.

He exhibited several maps of the camps and a large number of photo-
graphs specially pertaining to the work, and others of points of interest taken
during the campaign.

On motion, adjourned. J. F. Wilson, Secretary.

A

SSOCIATION

OF

Engineering Societies.

Vol. XXIII. OCTOBER, 1899. No. 4-

PROCEEDINGS.

Engineers' Clul) of St. Louis.

494TH IMeeting, October 4, 1899. — The meeting was called to order at 8
P.M. ; President Colby presiding. Sixteen members and three visitors were
present. Messrs. Fogarty, Fay, Bilhartz, Ringer, Cordes and Beardslee, hav-
ing been recommended for membership, were balloted for and all declared
elected.

The paper of the evening, entitled "The Development of the Automatic
Machine for Metal Working," was then read by Mr. H. S. Wilson. The
probable incidents that led to the invention of the earliest and crudest form
of machinery were given, together with short descriptions of the machines.
The author then went on to give brief descriptions of old but more modern
forms of automatic machines, showing how automatic machines of yesterday
become the semi-automatic or non-automatic of to-day by reason of constant
improvement.

The machines used for automatically making a large variety of articles
were briefly described, and some of the wonderful results achieved with
them noted.

Mr. McFarland exhibited some samples of automatic machine work.

There being no further business, the meeting adjourned.

E. R. Fish, Secretary.

495TH Meeting, October 18, 1899. — The meeting was called to order at
8.15 P.M. ; President Colby presiding. Thirty-two members and twelve visi-
tors were present. The minutes of the 494th meeting were read and ap-
proved. The name of Mr. Jos. Boyer was proposed for membership. The
paper of the evening, on "The Design and Construction of a Modern Central
Station," was then read by Mr. H. H. Humphrey. A brief resume of the
legislation creating the underground conduit system for electric wires was
given, and also the conditions influencing the organization of the Imperial
Electric Light, Heat and Power Company. The conditions governing the
design of the plant were fully entered into and afterward a general descrip-
tion given of the various parts of the equipment, both mechanical and elec-
trical, and also of the conduit system and method of distribution. The paper
was illustrated by lantern slides shown as referred to in paper.

The discussion following was participated in by Messrs. Wilson, Hol-
man, Bryan, Reeves, Borden and Kinealy. There being no further business,
the meeting adjourned. E. R. Fish, Secretary.

ASSOCIATION OF ENGINEERING SOCIETIES.
Techuical Society of the Pacific Coast.

Regular Meeting, October 6, 1899. — Called to order at 8.30 p.m. by
President Percy. The minutes of the last regular meeting were read and
approved.

Mr. Stephen E. Kieffer, civil engineer, Sacramento, was elected to mem-
bership by regular ballot.

A letter was read from the Southern Pacific Company, stating rates at
which a car may be had for the purpose of a Society excursion to Palo Alto
and Greystone Quarry.

It was ordered that the Secretary circulate notices, requesting members
to notify the Society of their willingness to attend this outing to visit the
Memorial Arch now building on the Stanford University grounds, and to
inspect the neighboring quarries ; and that the date of the excursion be set
for Saturday, October 14. (This date was subsequently postponed to Octo-
ber 21, and, on account of the inclemency of the weather, again postponed
until October 28.)

Mr. Max Junghaendel, a visiting architect, discussed the plans and de-
signs for the State University buildings, adopted by the late jury in the
Phoebe Hearst competition, and criticized at length the various features of a
design so vast and costly, which could not be realized under any of the
ordinary conditions of time and adequate appropriations. This criticism was
discussed by a number of visiting architects and engineers.

It was moved that the President and Secretary confer with Mr. J.
Reinstein, and to ask of this gentleman the courtesy of permitting Mr.
Junghaendel to take photographs of the various plans and drawings sub-
mitted to the jury by competing architects. Carried.

Adjourned. Otto von Geldern, Secretary.

Detroit Eiigiueering- Societj'.

The 43d regular meeting of the Detroit Engineering Society was held at
the Hotel St. Claire, October 27, President Keep presiding. Minutes of the
last meeting read and approved.

Mr. E. S. Reid was elected a member of the Society, and the name of
Mr. F. A. Little was proposed for membership and referred to the Executive
Committee. The paper of the evening was read by Mr. David Molitor, and
was illustrated by blackboard sketches. The paper was discussed by Messrs.
Williams and Dow. A vote of thanks was extended to the speaker of the
evening. Attendance twenty-six. Meeting adjourned at 10.45 p.m.

T. H. HiNCHMANj Jr., Secretary.

Enariueers' Club of Cincinnati.

109TH Regular Meeting, Cincinnati, Ohio, October 19, 1899. — Dinner
was served at 6.15 p.m. Fourteen members and one visitor present.

The regular meeting was called to order at 7.35 p.m., Vice-President
Punshon in the chair.

Minutes of the meeting of September 21 were read and approved.

On ballot being taken, Mr. Frank L. Fales was elected to active member-
ship.

PROCEEDINGS. 13

Mr. David Goldfogle read the paper for the evening, on "Some Details
of Two Sewer Tunnels." The first part of the paper comprised a description
of the construction of a brick sewer 11 feet in diameter, about 300 feet long,
which was tunneled through the embankment supporting the Miami Canal at
a point a short distance south of the Mitchell avenue aqueduct. At this
point there existed an old stone culvert, semicircular in shape, from 5^ to 6
feet in height and about 12 feet in width at the bottom, which had been
built at the time of the construction of the canal. This culvert had for its
foundation a layer of hewn oak logs, about 10" x 12", laid close together and
extending a short distance beyond the sides of the culvert. This old culvert
was in very bad condition, the mortar having fallen from the joints, leaving
large holes in the sides and top, necessitating great care in the construction
of the new sewer, which was so located with reference to the old culvert
that its bottom was about 8^ feet below the top of the old timber floor at
the west end and about 5^ feet at the east end.

A wooden flume was constructed on top of the timber floor to carry
the creek water during the construction of the lower half of the sewer. When
this lower half had been completed for the entire length up to the timber
floor, the old culvert being supported in the meantime by means of wooden
struts and beams as the work progressed, the water was turned into it, the
timber floor was cut away in sections and the upper half of the circular
sewer built inside the old culvert, beginning at the middle and progressing
each way. The space between the top of the new sewer and the inside of the
old culvert was filled in solidly with brickwork. The total cost of the work
to the contractor was about $22 per lineal foot of sewer.

The second part of the paper was devoted to a description of the method
of constructing a tunnel for a 16-inch cast iron pipe sewer to replace a
damaged 15-inch pipe sewer. The material encountered was blue shale and
rock, and required blasting for its removal. The material was conveyed to
the surface through shafts, in some of which brick manholes were built, the
others being used simply for the purpose of facilitating construction and were
filled up after the work was completed. The tunnel, after the pipe was laid,
was filled with concrete to the center line of the pipe and the excavated ma-
terial placed back on top of the pipe, completely filling the tunnel.

Illustrative maps and plans accompanied the paper, and after the reading
of same a general discussion followed.

Mr. Elzner described briefly the septic system of sewage disposal.

Adjourned. * J. F. Wilson, Secretary.

Ass

OCIATION

OF

Engineering Societies.

Vol. XXin. NOVEM BER, 1899. No. 5.

PROCEEDINGS.

Technical Society of the Pacific Coast.

Regular Meeting, November 3, 1899. — Called to order at 8.30 p.m. by
President Percy. The minutes of the last regular meeting were read and
approved.

Mr. George Johnston, mechanical engineer, of San Francisco, applied
for membership ; proposed by G. W. Dickie, John Richards and G. W.
Percy. The application was referred to the Board of Directors.

Mr. John Richards, Past-President, addressed the Society on the sub-
ject of "Patents and Monopoly," which was discussed at length by members
present.

It was suggested by the author of the paper that a committee be ap-
pointed to inquire into and note the method of procedure followed by the
U. S. Patent Office in the matter of determining the merits of a claim and
granting the patent privileges. Also to compare these methods with those in
vogue in foreign countries, and to report the results of these studies to the
Society.

Mr. Dickie moved that a committee of three be appointed by the chair,
and that the President be granted until the December meeting to select from
the membership a suitable committee for this purpose. Carried.

The meeting thereupon adjourned.

Otto von Geldern^ Secretary.

Engfineers' Society of Western New York.

The Engineers' Society of Western New York was delightfully enter-
tained November 6, 1899, by a lecture, entitled "An Excursion to Egypt and
Europe," delivered by Mr. Howard A. Carson, member Am. Soc. C. E., and
a prominent engineer of Boston. The lecture was replete with interesting
information, pleasingly illustrated by stereopticon views.

Boston Society of Civil Eng-ineers.

Boston, Mass., October 18, 1899. — A regular meeting of the Boston So-
ciety of Civil Engineers was held at Chipman Hall, Tremont Temple, at 7.50
o'clock P.M. ; President C. Frank Allen in the chair. Fifty-eight members
and visitors present.

i6 ASSOCIATION OF ENGINEERING SOCIETIES.

The record of the last meeting was read and approved.

Messrs. George Corrie Bartram, Frank Harrie Carter, William Lewis
Clark and William Vaughan Polleys were elected members of the Society,
twenty-five votes having been cast, all in the affirmative.

The amendment to By-law 5, which was reported at the last meeting,
and which had been printed in the notice of this meeting, was then taken up.
On motion of Mr. E. W. Howe, duly seconded, the amendment was adopted,
twenty-three voting in the affirmative and one in the negative. As amended
the second paragraph of By-law 5 reads as follows :

"Of the candidates for any office, the one having the largest number of
legal votes by letter ballot shall be elected. Should there be a failure to
elect any officer on account of a tie, the meeting shall proceed to elect such
officer by ballot from among the candidates so tied; a majority of the votes
cast being required to elect."

The President announced the deaths of three members of the Society.
Sumner Hollingsworth died June 26, 1899; John H. Blake died July 5, 1899,
and Samuel Nott died October i, 1899. On motion of Mr. L. F. Rice, the
President was requested to appoint committees to prepare memoirs. The
following committees have been named by the President:

On Memoir of Mr. Hollingsworth, Messrs. J. R. Freeman and Chas. T.
Main ; on Memoir of Mr. Blake, Messrs. Fred. Brooks and Wm. B. Fuller,
and on Memoir of Mr. Nott, Messrs. L. B. Bidwell and Edward Sawyer.

Mr. Walter B. Snow was then introduced and read an exceedingly in-
teresting and valuable paper, entitled "Mechanical Draft for Steam Boilers."
The paper was profusely illustrated with lantern views.

At the conclusion of the reading of the paper, on motion of Mr. F. P.
Stearns, the thanks of the Society were voted to Mr. Snow.

Adjourned. S. Everett Tinkham, Secretary.

Eiis>iueers' Club of St. Louis.

497TH Meeting, November 15, 1899. — Meeting was called to order at
8.20 P.M. ; President Colby presiding. Twenty-three members and six visi-
tors were present. The minutes of the 496th meeting were read and
approved. The minutes of the 281st meeting of the Executive Committee
were read. It was moved and seconded, and the motion carried, that a
Nominating Committee, to report at the following meeting, be elected. The
result of the ballot was the election of Messrs. Russell, Holman, Bryan, Flad
and Kinealy as a Nominating Committee.

The presentation of the 1898 Vol. of the Trans, of the Am. Inst, of Min.
Engrs. by Col. E. D. Meier was announced, and a vote of thanks tendered
the donor.

Prof. J. L. Van Ornum then read his paper on "The Volunteer Engi-
neers in the War with Spain." A brief history of the formation of the
engineer regiments was given and mention made of the numerous military
duties and drills in which the regiments received thorough instruction. Be-
sides the purely military features, the various engineering duties of these
troops were explained, many of them being enumerated in detail. A short
description of character of the actual work done by the Third Regiment
while in Cuba was given. The paper was supplemented by a series of views,
which were fully explained by the speaker.

The discussion was participated in by Messrs. Colby, Bryan, Kinealy,
Nipher and Spencer. E. R. Fish, Secretary.

PROCEEDINGS. i?

Montana Society of Eng-ineers.

A MEETING of the Society was held in the art room of the Butte Public
Library, Butte, Montana, on November ii, 1899.

Meeting called to order by President Eugene Carroll, at 8.30 p.m.; Mr.
R. A. McArthur acting as Secretary pro tern.

The application for membership of Edmund B. McCormick, of Boze-
man, Mont., was read and referred to the Trustees. The Secretary was
instructed to send out letter ballots on the applications of R. R. Vail,
Albert Koberle and Daniel J. McNally for membership.

Mr. Carroll, of the Transportation Committee, reported progress, sat-
isfactory arrangements having been made with most of the railway com-
panies for rates to the annual meeting, which occurs on the second Sat-
urday in January. It was decided to hold the regular annual meeting of the
Society at Bozeman, Mont.

The President appointed the Committee of Arrangements for the an-
nual meeting as follows, — viz: Wm. H. Williams and Clayton H. Thorpe,
both of Bozeman, and Frank L. Sizer, of Helena.

A letter from Vice-President M. S. Parker, relative to members from
Utah, was referred to the annual meeting. The Secretary was instructed
to call the December meeting for Butte, whereupon the Society adjourned.

A. S. HovEY, Secretary.

Engineers' Club of Cincinnati.

iiOTH Regular Meeting. Cincinnati, O., November 16, 1899.

Dinner was served at 6.20 p.m. Fourteen members present.

The regular meeting was called to order at 7.30 p.m., with Mr. Wm. C.
Jewett in the chair.

Minutes of the meeting of October ig were read and approved.

One application, for associate membership, was presented.

Mr. Alfred Petry read the paper for the evening, on "The Evansville
Caisson." This caisson was built in 1896 and forms the bottom of the
pump pit for the pumpjng station of the water works at Evansville, Ind. It
is built of white oak and is circular in plan, with an outside batter, being
a frustrum of a cone, 16 feet high, and with its top and bottom diameters
77 feet 6 inches and 80 feet 2 inches respectively. The roof is 8 feet thick,
leaving a height of 8 feet for the working chamber.

The paper treated of the plan of construction of the caisson and the
manner of sinking it to place, which was, for a part of the distance, by the
use of compressed air, the apparatus for which was described in detail.

The caisson supports a stone masonry well, circular in shape, 53 feet in-
side diameter and 61 feet high, the wall of which is 12 feet 3 inches thick
at the bottom, tapering to 4 feet at a point 17 feet from the top, and above
that point continues the same thickness to the top. In this well are located
the three pumping engines.

The paper was illustrated by a large sketch of the caisson and a number
of photographic views at different stages of construction.

The reading of the paper was followed by a general discussion of the
subject.

Adjourned. J. F. Wilson, Secretary.

A

SSOCIATION

OF

Engineering Societies.

Vol. XXIII. DECEM BER, 1899. No. 6.

PROCEEDINGS.

Engineers' Society of Western New York.

The fifth annual meeting of the Engineers' Society of Western New
York was held in the rooms of the EUicott Square Club on December 4, 1899.

Meeting called to order at 8 o'clock p.m. ; Mr. Haven, chairman.

The following members and guests were present :

Messrs. March, Babcock, Tresise, Powell, Gorman, Dr. George Fell,
Speyer, Pihl, Symons, Young, Mayor Diehl, Ricker, Haven, Eighmy, But-
tolph, Knighton, Bassett, Houck, Kielland, Lewis, Clark, Rogers, Roberts,
Fruauff, Rockwood, Diehl, C. F. Fell, Bardol, Knapp, Quintiss, Elliott,
Wilson, Sornberger.

The minutes of the meeting of November 6111 were read and approved.

The report of the Secretary, Mr. March, was read, received and filed.

REPORT OF THE SECRETARY.

Mr. President and Gentlemen:

Inasmuch as there were no annual reports presented a year ago, I wish
tc state briefly the work for 1898 :

At the January meeting we were pleasingly entertained by Mr. E. C.
Lufkin with a paper entitled "Pipe Lines."

February we were notified that the Society had been admitted as a mem-
ber of the Association of Engineering Societies.

March, an instructive paper by Prof. R. C. Carpenter upon "Laboratory
Experimental Work at Cornell University."

April, Major Symons presented the timely topic, "Coast Defenses and
Fortifications," after which a light lunch was served at the rooms.

May, Mr. George W. Rafter gave an interesting paper on "The Run-Off
of Niagara River."

June, report of the Reception Committee's work in welcoming the Con-
vention of American Society of Mechanical Engineers, held at Niagara
Falls.

Mr. W. S. LIunbert then delivered an exhaustive paper upon "Cement —
Its Origin, History, Tests, Specifications, etc."

September, Mr. H. L. Noyes gave an interesting paper on "The Early
History of Bridges."

October, Mr. T. Guilford Smith delivered a very comprehensive paper
entitled "Important Works in Egypt."

20 ASSOCIATION OF ENGINEERING SOCIETIES.

The matter pertaining to the formation of a State Society looking toward
efifective legislation regarding the practice of engineering was laid on the
table.

During October the American Society 'of Mining Engineers held one of
its stated meetings in Buffalo, and our Society contributed largely to the
entertainment of the convention, by various committees appointed to impart
information, etc., and welcome the visitors, etc.

As there was no regular election of officers in December, 1898, the old
officers retained offices during the year 1899.

At our regular March meeting we were favored by Mr. F. V. E. Bardol
with an interesting talk upon "The Abatement of the Hamburg Canal Nui-
sance."

March 21, 1899, we held a special meeting to take action upon the pre-
liminary plans of sites for the Pan-American Exposition, as the matter had
been referred jointly to the Engineers' Society of Western New York and
the Buffalo Chapter of Architects, by resolution of the directors of the
Exposition Company.

At the special meeting held on June 15, the Secretary had the pleasure
of reporting that nineteen new members had been elected.

The October meeting was full of enthusiasm and interest for the better-
ment of the Society.

At our November meeting we and lady friends were pleasingly enter-
tained by Mr. Howard A. Carson, Mem. Am. Soc. C. E., a prominent en-
gineer of Boston, who gave us a lecture entitled "An Excursion to Egypt
and Europe," accompanied by stereopticon views.

This fifth annual meeting to-night will speak for itself, and I hope will
live pleasantly in your memory for a long time.

The Society now numbers about fifty-four members.

Respectfully submitted,

H. T. March,
Secretary for i8g8 and iSqq.

Report of the Treasurer, ]Mr.' Bassett, was read, received and filed.

REPORT OF THE TRE.\SURER 1898-1899.

Cash on hand, December 15, 1897 $366.72

Received from Secretary to November 24, 1899 598.70

Total $965.42

Disbursements of sundry kinds $746-53

Permanent fund 80.00

Balance in bank 138.89

$965.42

George B. Bassett, Treasurer.

Messrs. Ricker and Roberts were appointed as tellers to canvass the vote
of the Society.

After dinner the tellers reported that the following gentlemen were
elected for the year 1900 :

President — Mr. W. A. Haven.

Vice-Presidents— H. J. March, C. H. Tutton.

Secretary — George Diehl.

PROCEEDINGS. 21

Treasurer — George R. Sikes.

Director — E. C. Lufkin.

Librarian — ^J. A. Knighton.

]Mr. Haven declared the above-named officers duly elected for the en-
suing year.

In the absence of Mr. Johnson, retiring President, Mr. Ricker, Past-
President, delivered an address, in which he referred to certain features of
the early history of the Society, and particularly to its entertainment of the
American Society of Mechanical Engineers at Niagara Falls, an entertain-
ment in which Mr. Johnson took an active part. Mr. Ricker emphasized the
benefits which this Society can confer upon the engineers of Buffalo and of
Western New York.

i\Ir. Haven, President-elect, expressed his appreciation of the honor
conferred upon him by his election, and urged the importance of measures
for making the members of the Society better acquainted with each other, of
providing a more suitable place for meetings, and of having the proceedings
published in the daily newspapers.

Hon. Conrad Diehl, Mayor of Buffalo, while claiming pre-eminence for
his own profession of medicine, paid high tribute to the skill of engineers
and to the importance of their work, calling attention to the bridge at Cob-
lenz, the iMont Cenis Tunnel, the Niagara bridges, the Buffalo breakwater
and the gorge road at Niagara as instances of such work.

AIr. HA\rEN. — The i\Iayor has spoken to you about the nobleness of the
medical profession, and that it is older than the engineering profession.
During the coming year if I can get a draughtsman that knows how to make
letters, I will give him something that was printed in 1645, entitled "The
Description of a Complete Engineer," which I would like to have copied in
prett}' large letters and hung in the new rooms of the Society, showing that
the engineering profession was known a good many years ago.

We would like to hear from some of the older engineers, and I will call
upon ]Mr. Young to address us. (Applause.)

Mr. Young, referring to the Mayor's claims for the medical profession,
called attention to the fact that the engineers were the pioneers of civiliza-
tion, and that, while they could not rise superior to the necessity for medical
science, that part of the work was often performed by a member of the en-
gineer corps.

Mr. Haven. — I take pleasure now in introducing to you Major Symons,
who, I think, is well known to you all. (Applause.)

^Iajor Symons. — Mr. President and Gentlemen, the chairman of your
committee has asked me to make a few remarks on the prominent features of
the Government work in and about Buffalo, and I will endeavor to do so. It
is rather a dry subject, but Mr. Ricker has provided something to wet it.

Very early in its history the people of Buffalo interested the general
Government in their harbor, and throughout all the developments which
have made this one of the great ports of the world, the general Government
has been in active partnership with the people of Buffalo.

The fir.st appropriation made by the general Government for the benefit
of Buffalo harbor was one of $15,000, away back in 1826. Since then the
amount expended by the Government for the benefit of Buffalo harbor has
been about $5,000,000. It is not very difficult to imagine what a struggling
little village Buffalo was at the time of the first appropriation; a few houses

22 ASSOCIATION OF ENGINEERING SOCIETIES.

down near the mouth of the creek, and a few hundred people gathered there,
and woods and prairies all about. But the Erie Canal had just been com-
pleted and the hopes of the people were high, and there was no limit to their
ambition. They had already, with money borrowed from the State, been
endeavoring to improve the entrance to the harbor by dredging and building
piers. The harbor inside the creek could be reached only with difficulty by
the small sailing vessels of the period, and when in the creek these vessels
were subject to damage from the lake rising under the influence of the
Western winds and piling across the narrow neck of fand separating the
creek from the lake, and threatening to wash this neck away.

The earliest and most important features of the improvement work
andertaken by the general Government were the construction of the piers at
the entrance to the creek. It can readily be understood that without these
piers the entrance must have been uncertain and dangerous, and especially so
to the sailing craft of those early days. For many years a long struggle went
on to build and maintain the south pier at the entrance channel. This pier,
before the breakwater was built, was fully exposed to the terrific storms of
Lake Erie, and it was repeatedly breached and in some instances carried
away. When this happened, a little more money would be appropriated, and
the pier would be patched up again and again. The history of this pier is
almost pathetic as indicating the struggle made by the engineers, with little
money and under many adverse circumstances, to maintain it against the
fearful power of Lake Erie. To all of those who have been down to it and
examined it the great strength which it was found necessary to give it is an
indication of its importance and of this struggle.

The building and maintenance of the north pier was a much simpler
problem, as it was protected against the worst storms by the south pier.
There is no danger of this north pier getting away now, as it is being held
down very securely by the Delaware and Lackawanna Railroad.

One of the earliest works imdertaken by the general Government was to
build a seawall to protect the neck of land lying between the lake and the
inner creek, the harbor of BuiYalo. This seawall is still in existence, although
it is not now needed, having been supplanted by the outer breakwater, which
takes its place as a barrier against the sea. Besides the good it did at the
time, the construction of this seawall was a means of the city acquiring a
heritage of very great value; this is the strip of land about 7000 feet long and
13s feet wide on which -the seawall was built. By legislative action the city
has been possessed of this strip of land for highway purposes, and I hope
that it will soon tal^e action to clear this ofT and convert it into a grand com-
mercial highway running along the 'harbor front. I also hope that some
means will be found to extend this grand future highway along the harbor
front all the way to Stony Point. The existing Hamburg Turnpike would
furnish the nucleus for such an extension, and I am going to ask you all as
brother engineers to do everything in your power to bring this about, so that
we can have a broad highway suitable for all purposes extending along the
entire front of the new and great harbor of Buffalo.

The Mayor has brought this matter before the City Council and is trying
with all his might to get this highway laid out and properly utilized, and the
city of Buffalo is greatly indebted to Mayor Diehl for his stand on this
question. But something besides the seawall and the entrance piers became
necessary in the development of Buffalo harbor, and a breakwater was de-

PROCEEDINGS. ■ 23

signed to cover the entrance between the piers. Buffalo wanted this break-
water, and it got it. At tirst it was designed to be 2000 feet long; it was
afterwards extended and extended until it finally reached a length of 7600
feet, about one and one-half miles. This was its length when I came to
Buffalo about four 3-ears ago. When I came here in 1895 to take charge of
the Government improvement works, there were two parties in the field, one
which desired that the breakwater should not be extended farther, but with
a return breakwater should be built connecting its southern end with the
shore, thus making an outer harbor extending from the present harbor en-
trance about one and one-half miles to the south. The other party was in
favor of extending the breakwater entirely through to Stony Point, about
two and one-half miles farther. The latter party won, and the Government
adopted the project and the work was started and is now well under way of
building the breakwater from the soitthern end of the old breakwater entirely
through to Stony Point. This work has been imder way for about three
years and will cost when completed about $2,000,000, and will in itself be the
longest breakwater in the Avorld, and if we consider it in connection with the
old breakwater, the two together will make a breakwater defense against the
seas at least 50 per cent.. longer than any similar structure in the world.

About half of this breakwater at its southern end is to be timber crib
structure, which does not differ in any marked degree from similar timber
structures built here and elsewhere on the lakes. It does differ, however, in
some of its constructive details, and it differs also from any other breakwater
that has been built in the care and expense necessary to give k a good founda-
tion. In this portion of the work the water in which it is situated is about
30 feet deep; the mud overlying the rock is from 30 to 40 feet deep, and
through this mud there has beon excavated an enormous trench reaching
doAvn to the underlying rock. This trench has a width of 60 feet on the
bottom and an average depth of about 35 feet from the lake bottom to the
rock. It was excavated by a dredge especially built for the purpose, and
which I should have been very glad to have had you all see in operation.
It has, however, finished its work and has been taken to the seacoast to do
other work there. The trench thus excavated was filled with gravel dug
out of the Niagara River down near the International Bridge. Upon the
foundation so prepared the timber crib breakwater was built. It is expected
that the part under water will endure practically forever, and that the part
above water will last twenty to twenty-five years, and then will be replaced
with a concrete superstructure.

About half of this new breakwater is composed entirely of imperishable
materials, stone and gravel, no wood being used in it. This portion of the
work is unique in a number of respects. It is the first stone breakwater of
anything like.its character to be built upon the Great Lakes and it is the first
breakwater in the world, as far a-s I know, in which a hearting composing
about one-half of its bulk is made of gravel. This gravel hearting saves
about $600,000 in the cost of this portion of the breakwater, and renders it
possible to complete the work within the amount which Congress was willing
to allow. The cross-section of this stone breakwater was designed after a
careful study, and its lines are practically the lines which would be developed
by the action of storms upon an ordinary loo-e pile of stones. Taking this
as a cross-section, we have added to its stability by covering it over from the
top to a depth of 15 feet with huge stones carefully quarried out and care-

24 ASSOCIATION OF ENGINEERING SOCIETIES.

fully set in place. The contractors for the work were especially fortunate
in getting a quarry from which they can get almost ideal stone for this pur-
pose. This stone breakwater is unique in the way in which it is covered with
a pavement of three enormous capping stones. No breakwater has even
been built with natural stones of as great size and good quality and shape,
and with these stones as carefully placed and bonded together as has this
Buffalo breakwater, and I am confident that when it is finally completed and
becomes known to engineers it will be regarded as one of the most monu-
mental breakwater structures in the world.

In order that nothing should be left undone which the Government could
do for Buffalo, the last session of Congress provided money for the building
of a north breakwater to cover the shore area lying between the Bird Island
pier and the Erie Basin, and this work has also been started, and we hope to
finish it next year. This north breakwater is to be a timber crib substructure,
and concrete and stone superstructure.

There are a good many otlier things which the Government has done
and is constantly doing for the commerce of Buffalo, but I will not take up
your time more than to mention in a very general way a few of them.
There is the building and maintaining of the lighthouses marking the en-
trance to the harbor, and the entrance to Niagara River ; there are five of
these lighthouses right here ; there are a number of buoys marking channels
and shoals which are maintained by the Government ; there is a large and
constant expense for maintenance of the breakwater and pier structures, and
the Government. also at a considerable expense maintains a supervision over
the navigable waters, looking out to see that they are not encroached upon
in any wrongful manner.

There is a Governmental engineering project afoot in which the people
of Buffalo, and particularly the engineers of Buffalo, must naturally take
great interest. I allude to the proposed dam at the head of the Niagara
River for the regulation of lake levels. The Deep Waterways Commission
has been studying this problem for some time and I believe it is a work that
is sure to come. The broad interests of lake commerce demand it, and we,
here in Buffalo, must look at it from this broad viewpoint and at the same
time see that the interests of Buffalo harbor and Niagara River are properly
guarded. The proper designing of this dam, to hold back the waters at low
stages of the lake and let them run off freely at high stages and at the same
time provide for the navigation of the Niagara River, is a problem of the
greatest interest, complexity, magnitude and importance.

The details of the plans of the Deep Waterways Commission have not
yet been made public, and hence I do not feel at liberty to discuss them.
When they do come they will certainly attract the attention of every engineer
here.

I believe that it can safely be affirmed that there is no other country in
the world which gives such liberal and efficient aid to its people in develop-
ing their commercial facilities and I hope that what little I have said may
cause you all to feel as I do, that in all that relates to the interest and good
of Buffalo, the Government is an active and efficient partner. (Applause.)

Mr. Haven. — As the officers of the United States Army are liable to be
sent here, there and everywhere, it is hardly fair to ask them to become
regular members of this Society ; and I would ask some one to request me to
recommend to the Executive Committee that ]\Iajor Symons be made an hon-
orary member of this Society. (Applause.)

PROCEEDINGS. 25

Mr. Ricker. — Mr. President, I would move that you recommend to the
Executive Committee that Major Symons be made an honorary member of
this Society. Seconded by Mr. Bardol. Carried.

Mr. Ricker. — Mr. President, I Avould also move that you recommend to
the Executive Committee that the JNIayor of our city, the Hon. Conrad Diehl,
be made an honorary member of our Society. Seconded by Mr. Bassett.
Carried.

Mr. Rockwood, division engineer of the Erie Canal, urged the importance
of measures for popularizing the Society and of increasing its library.

Mr. Ricker offered the following :

Resolved, That it is the sense of this Society that the Mayor's action of
this day in recommending the appointment of a commission to investigate the
matter of the seawall strip and to deal with the subject of this proposed great
commercial highway along the water front be indorsed.

Seconded by Mr. Bassett and carried unanimously.

Mr. Bassett. — I would move that Major Symons' invitation to the So-
ciety to get out to view the breakwater at some time next summer be ac-
cepted now, and that the President be instructed to arrange with Major
Symons for some date.

Mr. George Diehl. — I will second the motion. It is very courteous of
Major Symons to invite us to inspect the breakwater. It is a very important
and interesting piece of work.-

-\Ir. Roberts. — I second the motion. Carried.

Mr. March. — The individual members of the Society have received a
communication from the Director of the United States Geological Survey,
giving a list of the topographical maps issued by that department, and I
would move that the Secretary be directed to procure a set of the maps of
New York State as issued by that department for the use of this Society, at
whatever expense may be incurred in securing them.

Seconded by Mr. Roberts. Carried.

Interesting talks were given by ]Mr. Lewis on the street railway work in
Buffalo, by Mr. Kielland on railway construction in South Africa, which
was especially interesting at the present time, as Mr. Kielland was assistant
engineer in the construction of the railroad that runs through Ladysmith.
After short talks by various other gentlemen present the meeting at midnight
adjourned. G. C. Diehl, Secretary.

Engineers' Club ot St. Louis.

498TH Meeting, December 6, 1899. — Meeting was called to order at 8.25
P.M. ; President Colby presiding. Twenty-two members and one visitor were
present. The minutes of the 497th meeting were read and approved. The
minutes of the 282d meeting of the Executive Committee were read. The
Nominating Committee made its report with the following nominations :

For President — W. S. Chaplin.

Vice-President — E. J. Spencer.

Secretary — F. C. Bausch.

Treasurer — E. R. Fish.

Librarian — J. L. Van Ornurn.

Directors — B. H. Colby, Wm. Bouton.

26 ASSOCIATION OF ENGINEERING SOCIETIES.

Board of Managers of Association of Engineering Societies — W. A. Lay-
man, E. A. Hermann.

There being no further nominations, it was moved and seconded and the
motion carried that nominations be closed.

The annual reports of the President and Secretary were read and on
motions duly seconded were received and filed. The Treasurer's report was
read by the Secretary, and on motion was referred to the Executive Com-
mittee.

On behalf of the Committees on Eads Monument and Smoke Preven-
tion, Mr. Robert Moore made verbal reports.

Report of the Entertainment Committee was received and filed.

It was moved and seconded that the arrangements for the annual dinner
be left to the Executive Committee. Motion carried.

Mr. Moore suggested that some action be taken toward filling out gaps
in the files of the publications of the United States Engineers Department in
the Club's Library.

Professor Nipher announced that he had nearly completed preparations
for the measurement of wind pressures along the sides of the large University
Building, which has a front of over 200 feet, and a depth of 45 feet. Simul-
taneous measurements will be made along the faces of the building, and the
wind direction will be accurately determined at the instant of each pressure
measurement. An invitation was extended to members and others who may
be interested to at any time inspect the apparatus.

He also gave some explanation of the details of the apparatus, and some
of the results of his experiments to calibrate the instruments.

The discussion was participated in by Messrs. Bryan, Colby, Kinealy
and Moore. Adjourned. E. R. Fish, Secretary.

499TH ]\Ieeting, December 20, 1899. — The annual dinner of the Club
was held at the Mercantile Club at 7.30 p.m. ; President Colby at the head of
the table. Forty-one members and seven visitors were present. After the
dinner was finished the officers for the new year were announced, as follows:

President — W. S. Chaplin.

Vice-President — E. J. Spencer.

Secretar}' — F. E. Bausch.

Treasurer — E. R. Fish.

Librarian — J. L. Van Ornum.

Directors — B. H. Colby, Wm. Bouton.

Members of Board of Managers of Association of Engineering Societies
— W. A. Layman, E. A. Hermann.

Mr. Colby then surrendered the chair to the new President, who presided
the rest of the evening.

Mr. Colby read an extremely interesting address on "Water Pollution,"
drawing a picture of the results of the emptying of Chicago's sewage into the
Mississippi River, and showing the necessity for legislative action.

Mr. W. S. Chaplin made a short talk on "Engineering Ideals."

^Ir. W. H. Bryan on the "Paris Exposition."

Capt. Edw. Burr on the "Engineer in Military Operations."

Mr. J. A. Ockerson on the "Father of Waters," and Mr. W. A. Lay-
man on the "Engineering Panorama."

Following these a number of short speeches were made by several others.

E. R. Fish, Secretary.

PROCEEDINGS. 27

Montana Society of Engineers.

A MEETING of the Society was held in the art room of the Butte Public
Library, Butte, Mont., on December 9, 1899.

Meeting called to order by Vice-President Frank L. Sizer, at 8.30 p.m.,
Mr. R. A. McArthur acting as Secretary pro tern.

The application for membership of Edmund B. McCormick, of Bozeman,
Mont., was read, and the Secretary instructed to send out the usual letter
ballots.

Messrs. M. L. Macdonald and William Zaschke were appointed as tellers
to canvass the ballots on membership, whereupon the chair declared Richard
R. Vail and Albert Koberle to be duly elected members of the Society.

The report of the Nominating Committee of the officers for the ensuing
year was read and on motion adopted, and the Secretary instructed to send
out the usual letter ballots.

A preliminary report from the Committee on Arrangements for the
thirteenth annual meeting, at Bozeman, Mont., was read and adopted.

Adjourned. A. S. Hovey, Secretary.

Technical Society of the Pacific Coast.

Regular Meeting, December i, 1899. — Held in the main hall of the
Academy of Sciences, and called to order at 8.30 p.m., by Vice-President
Hubert Vischer.

The minutes of the last regular meeting were read and approved.

Mr. George Johnston, mechanical engineer, of 326 Oak street, San Fran-
cisco, was elected to membership upon a count of ballots.

Mr. Harry Larkin, manufacturer, San Francisco, applied for associate
membership. Proposed by G. W. Percy, E. T. Schild and Adolf Lietz.

It being in order to select a Nominating Committee for the purpose of
choosing a list of officers for the ensuing year at this meeting, the following
members were elected by acclamation : C. E. Grunsky, H. C. Behr, Adolf
Lietz. Edward C. Jones and A. Ballantyne, who were instructed to prepare
a ticket and report at the next regular meeting.

Mr. Max Junghaendel thereupon addressed the Society on the subject of
"Hospital Arrangement and Construction," according to the most recent and
approved practice, criticising therein a number of plans for the proposed
city and county hospital, which were entered in competition by various local
architects.

A short discussion followed, after which the meeting adjourned.

Otto von Geldern, Secretary.

Civil Engineers' Society of St. Paul.

St. Paul, December 4, 1899. — A regular meeting of the Civil Engineers'
Society of St. Paul was held at 8.30 p.m. Present, nine members and one vis-
itor; President Estabrook presiding. Minutes of previous meeting read and
approved. Letter of acknowledgment from Mrs. Archibald Johnson read
and filed.

28 ASSOCIATION OF ENGINEERING SOCIETIES.

On motion of Mr. Powell, Mr. W. A. Truesdell was named to prepare
a memorial to our late fellow-member, Archibald Johnson, deceased October
3, 1899.

Mr. A. W. Miinster read a paper on the temporary bridge across the Mis-
sissippi River at Wabasha street, which paper he was requested to prepare for
publication in the Journal of the Association of Engineering Societies.

Capt. A. O. Powell presented a diagram and explained results obtained
with silica cement, which is being used in the construction of the United
States Government lock and dam No. 2 at this point. Interesting discussions
on lumber and cement occupied considerable time.

C. L. Annan^ Secretary.

Boston Society of Civil Engineers.

Boston, Mass., November 15, 1899.- — A regular meeting of the Boston
Society of Civil Engineers was held at Chipman Hall, Tremont Temple, at 8
o'clock P.M.; President C. Frank Allen in the chair. Sixty-one members and
visitors present.

The record of the last meeting was read and approved.

The President announced the death of William S. Whitwell, an hon-
orary member and one of the founders of the Society; and on motion of
Professor Swain the President was requested to appoint a committee to pre-
pare a m-cmoir. The committee named consists of Messrs. Francis Blake and
E. W. Bowditch.

On motion of Mr. Metcalf, the thanks of the Society were voted to the
Engineering Department of the city of Providence for courtesies extended
this afternoon on the occasion of the visit to that city.

Prof. A. H. Sabin then read a very interesting paper entitled "Protective
Coatings for Structural Metals." The paper was illustrated by an exhibit of
235 steel and aluminum plates which had been coated with various oils, var-
nish, paints and some special preparations, and had been immersed, part of
them in fresh water and part in salt water, for about two years. A discussion
followed the reading of the paper, in which Professor Sabin very kindly
answered numerous questions with regard to paints and coating for metal
work.

Mr. J. P. Snow gave a' description of the method used by the Boston and
Maine Railroad for cleaning its bridges in place by means of the sand-blast,
which had proved very satisfactory.

After passing a vote of thanks to Professor Sabin for his interesting and
instructive paper, the Society adjourned.

S. E. Tinkham, Secretary.

Civil Engineers' Clnb of Cleveland.

Regular Meeting, December 12. — President J. A. Smith in the chair.
Present twent}--five members and twenty visitors.

]\Iessrs. B. L. Green and E. E. Boalt appointed tellers to canvass ballots
for new members. Charles F. Dutton elected an active member and L. B.
Stouffer an associate member.

PROCEEDINGS. 29

Resolutions upon the death of Mr. Clarence A. Carpenter were read and
followed by appropriate remarks from several of the members.

Application for active membership by Mr. H. L. Olmstead was read and
referred to letter ballot.

Mr. Bernard L. Green, member of the Club, then read a paper entitled
"A Few Notes Regarding Grade Crossings and Their Treatment." A lively
discussion followed, taken part in by Messrs. J. A. Smith, Augustus Mor-
decai, N. P. Bowler, Ambrose Swasey, A. H. Porter, Wm. H. Searles and
H. C. Thompson.

Moved and carried, that the Club adjourn until December 26, for further
discussion, and that Mr. Augustus Mordecai read a paper on that date.

Adjourned, 10 p.m.

Arthur A. Skeels, Secretary.

Semi-Monthly Meeting, December 26. — President J. A. Smith in the
chair. Present twenty-five members, seven visitors.

No business was transacted.

Mr. Augustus Mordecai, assistant chief engineer of Erie Railroad, and
member of the Club, read a paper on "Grade Crossings." Discussion fol-
lowed, taken part in by Messrs. H. C. Thompson, C. H. Haupt, E. E. Boalt,
B. L. Green, James Ritchie, J. A. Smith and F. C. Osborn.

Adjourned at 10 p.m.

Arthur A. Skeels, Secretary.

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